Stalls on decelleration and when nose is down

Hi all,

I've been away for a while, enjoying the Wonderbus, and out camping in
our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
outfitting with low-power lighting, and solar panels. That way, Mrs
Squirrel has a cozy and happy little home to camp in which makes her
happy. A happy Mrs Squirrel means I get to camp more. And I love camping.

But enough about that. A problem has surfaced in the 71 Wonderbus. It
started out as an occasional thing a week or so ago, but it now happens
all the time.

After cruising at speed for a little bit (several seconds, a few
minutes, a while on the freeway, along a city street . . . just normal
driving), the engine stalls when I put in the clutch. This will occur
when I hit the freeway offramp, or just pull up to a stop sign. If I can
use the e-brake to stop and keep the foot on the gas and keep the rpm's
up above a thousand or so, it gets over it and will idle just fine when
I take the foot off the gas.

Once it dies, I can easily re-start it. There are no problem while
driving. Repeat: no problems while driving once the engine has
re-started. It idles fine, it drives fine. It's only after driving and
when the foot goes off the gas that the engine dies.

I notice that it also likes to die when the nose is downhill and the
engine is idling . . . like waiting on a downhill street and waiting for
a light to change or something.

I am going out on a diagnostic limb here (applying all my tiny rodent
brain cells and my minuscule experience and understanding of how The
Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
deceleration and nose-downhill conditions pull gas forward toward the
tank. If the pump is wimping out, it might starve the engine. Clue 2:
This is an older fuel pump that I took off the Wonderbus's failed 1776
engine and installed on the new Mexican Type 1 1600DP engine earlier
this year (or late last year, I forget). Anyway, when I was putting the
fuel pump on, I measured the throw of the rod that pushes on the pump's
diaphragm and it was almost less than the low side of the length
tolerance. Clue 3. At that time, I measured fuel pressure and it also
was on the low side. So I am voting for low fuel pressure as the cause
of this exciting new behavior.

Tomorrow I will tap into the output of the fuel pump and measure the
pressure.

While I am at it, I'd like to hear if anyone has any other good ideas of
what I might check into?

Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
aircooled.net), CDI, SVDA dizzie.
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR

snip...
>
> While I am at it, I'd like to hear if anyone has any other good ideas of
> what I might check into?
>
> Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
> aircooled.net), CDI, SVDA dizzie.
> --
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> KG6RCR

Could be as simple as a vacuum leak?

Not the same engine as yours but my 2.0L type 4 engine did exactly what you
are describing, turned out to be two little rubber elbows that had split on
the pipe between the inlet manifolds.

I'll be darned. I guess this diagnostic limb I went out on was strong
enough to hold me without breaking: the reason the Wonderbus's engine is
dying when the car is braking or sitting with the nose lower than the
rear does appear to be low fuel pressure, like I guessed.

For single-carb engines, Bentley's says we want 3 to 5 psi. The pump is
putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
the front of the bus, away from the pump and I guess the pump does not
have sufficient sucking power to keep it, er, up.

Next step: identify the cause of the low pressure. The bus accelerates
and cruises normally, so I don't think I have a restriction anywhere.
Bentley's says that the pump pushrod is supposed to extend 13mm (.511'')
beyond the upper face of the Intermediate Flange (Bentley's Type 2, Fig
4-3) at its maximum extension for proper pump operation. Mine's at
12.1mm (.476'') maximum. That's with NO gaskets between the Intermediate
Flange and the engine.

I recall reading someplace that one way to lengthen the rod is to weld a
little bead on the end and polish it . . . but I don't weld.

I do, however, have a belt sander. How about taking a little off the top
of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).

More better would probably be to buy a new pushrod . . . but what kind
of fuel pump does this engine have. Single-carb 1600 DP, so it is not a
side-mount. It does NOT exactly match up with any of the illustrations
in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
pump. And it's not the Fig 4-4 pump.

While the pump is out, I'll disassemble it and clean it and look for
problems there.

Am I sorta/kinda on the right track to solving this problem? Is the belt
sander Intermediate Flange modification, like, really stupid?

--
Mike Rocket J. Squirrel Elliott



On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:

> Hi all,
>
> I've been away for a while, enjoying the Wonderbus, and out camping in
> our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
> outfitting with low-power lighting, and solar panels. That way, Mrs
> Squirrel has a cozy and happy little home to camp in which makes her
> happy. A happy Mrs Squirrel means I get to camp more. And I love camping.
>
> But enough about that. A problem has surfaced in the 71 Wonderbus. It
> started out as an occasional thing a week or so ago, but it now happens
> all the time.
>
> After cruising at speed for a little bit (several seconds, a few
> minutes, a while on the freeway, along a city street . . . just normal
> driving), the engine stalls when I put in the clutch. This will occur
> when I hit the freeway offramp, or just pull up to a stop sign. If I can
> use the e-brake to stop and keep the foot on the gas and keep the rpm's
> up above a thousand or so, it gets over it and will idle just fine when
> I take the foot off the gas.
>
> Once it dies, I can easily re-start it. There are no problem while
> driving. Repeat: no problems while driving once the engine has
> re-started. It idles fine, it drives fine. It's only after driving and
> when the foot goes off the gas that the engine dies.
>
> I notice that it also likes to die when the nose is downhill and the
> engine is idling . . . like waiting on a downhill street and waiting for
> a light to change or something.
>
> I am going out on a diagnostic limb here (applying all my tiny rodent
> brain cells and my minuscule experience and understanding of how The
> Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
> deceleration and nose-downhill conditions pull gas forward toward the
> tank. If the pump is wimping out, it might starve the engine. Clue 2:
> This is an older fuel pump that I took off the Wonderbus's failed 1776
> engine and installed on the new Mexican Type 1 1600DP engine earlier
> this year (or late last year, I forget). Anyway, when I was putting the
> fuel pump on, I measured the throw of the rod that pushes on the pump's
> diaphragm and it was almost less than the low side of the length
> tolerance. Clue 3. At that time, I measured fuel pressure and it also
> was on the low side. So I am voting for low fuel pressure as the cause
> of this exciting new behavior.
>
> Tomorrow I will tap into the output of the fuel pump and measure the
> pressure.
>
> While I am at it, I'd like to hear if anyone has any other good ideas of
> what I might check into?
>
> Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
> aircooled.net), CDI, SVDA dizzie.


--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR

Sounds good to me. I don't know about your solution, but if the bolts
tighten up afterwards, why not? You may have to finish it wet sanding on a
piece of flat glass (with wet/dry paper of course) I do that in the sink
with water trickling continuously. (It must be perfectly flat and the two
surfaces must be somewhere close to parallel.)
-BaH
"Mike Rocket J. Squirrel Elliott"
m> wrote in message
...
> I'll be darned. I guess this diagnostic limb I went out on was strong
> enough to hold me without breaking: the reason the Wonderbus's engine is
> dying when the car is braking or sitting with the nose lower than the
> rear does appear to be low fuel pressure, like I guessed.
>
> For single-carb engines, Bentley's says we want 3 to 5 psi. The pump is
> putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
> the front of the bus, away from the pump and I guess the pump does not
> have sufficient sucking power to keep it, er, up.
>
> Next step: identify the cause of the low pressure. The bus accelerates
> and cruises normally, so I don't think I have a restriction anywhere.
> Bentley's says that the pump pushrod is supposed to extend 13mm (.511'')
> beyond the upper face of the Intermediate Flange (Bentley's Type 2, Fig
> 4-3) at its maximum extension for proper pump operation. Mine's at
> 12.1mm (.476'') maximum. That's with NO gaskets between the Intermediate
> Flange and the engine.
>
> I recall reading someplace that one way to lengthen the rod is to weld a
> little bead on the end and polish it . . . but I don't weld.
>
> I do, however, have a belt sander. How about taking a little off the top
> of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
>
> More better would probably be to buy a new pushrod . . . but what kind
> of fuel pump does this engine have. Single-carb 1600 DP, so it is not a
> side-mount. It does NOT exactly match up with any of the illustrations
> in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
> not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
> pump. And it's not the Fig 4-4 pump.
>
> While the pump is out, I'll disassemble it and clean it and look for
> problems there.
>
> Am I sorta/kinda on the right track to solving this problem? Is the belt
> sander Intermediate Flange modification, like, really stupid?
>
> --
> Mike Rocket J. Squirrel Elliott
>
>
>
> On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
>
> > Hi all,
> >
> > I've been away for a while, enjoying the Wonderbus, and out camping in
> > our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
> > outfitting with low-power lighting, and solar panels. That way, Mrs
> > Squirrel has a cozy and happy little home to camp in which makes her
> > happy. A happy Mrs Squirrel means I get to camp more. And I love
camping.
> >
> > But enough about that. A problem has surfaced in the 71 Wonderbus. It
> > started out as an occasional thing a week or so ago, but it now happens
> > all the time.
> >
> > After cruising at speed for a little bit (several seconds, a few
> > minutes, a while on the freeway, along a city street . . . just normal
> > driving), the engine stalls when I put in the clutch. This will occur
> > when I hit the freeway offramp, or just pull up to a stop sign. If I can
> > use the e-brake to stop and keep the foot on the gas and keep the rpm's
> > up above a thousand or so, it gets over it and will idle just fine when
> > I take the foot off the gas.
> >
> > Once it dies, I can easily re-start it. There are no problem while
> > driving. Repeat: no problems while driving once the engine has
> > re-started. It idles fine, it drives fine. It's only after driving and
> > when the foot goes off the gas that the engine dies.
> >
> > I notice that it also likes to die when the nose is downhill and the
> > engine is idling . . . like waiting on a downhill street and waiting for
> > a light to change or something.
> >
> > I am going out on a diagnostic limb here (applying all my tiny rodent
> > brain cells and my minuscule experience and understanding of how The
> > Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
> > deceleration and nose-downhill conditions pull gas forward toward the
> > tank. If the pump is wimping out, it might starve the engine. Clue 2:
> > This is an older fuel pump that I took off the Wonderbus's failed 1776
> > engine and installed on the new Mexican Type 1 1600DP engine earlier
> > this year (or late last year, I forget). Anyway, when I was putting the
> > fuel pump on, I measured the throw of the rod that pushes on the pump's
> > diaphragm and it was almost less than the low side of the length
> > tolerance. Clue 3. At that time, I measured fuel pressure and it also
> > was on the low side. So I am voting for low fuel pressure as the cause
> > of this exciting new behavior.
> >
> > Tomorrow I will tap into the output of the fuel pump and measure the
> > pressure.
> >
> > While I am at it, I'd like to hear if anyone has any other good ideas of
> > what I might check into?
> >
> > Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
> > aircooled.net), CDI, SVDA dizzie.
>
>
> --
>
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> KG6RCR

Thanks for the feedback. I think that my diagnosis must be incorrect,
though. Low fuel pump pressure should not cause the engine to die when
it is returned to idle. Someone who knows a lot more about these things
than I ever will e-mailed me to point out that there is enough fuel in
the carb bowl to let the engine run for a minute or so.

That notwithstanding, I am wanting to get the fuel pressure up to the
specified 3 to 5 psi range. I hoped that a longer pushrod would do the
job -- the 110mm rods from Jbugs.com (within driving distance) looked
perfect. But they actually measure at 106mm, and mine is 105mm. Their
shorter "100mm" pushrod measures 100mm. Maybe some other vendor, like
aircooled.net will have a longer pushrod.

Anyhoo, the Smarter Guy suggested that I probably have a vacuum leak in
the brake booster. This does line up with my experience that the engine
dies when returned to idle while I am either decelerating, or when the
bus is sitting nose down at a red light. In both cases, I am using the
brake.

So I'll paste this thing together and check to see if the engine dying
is related to brake usage.

--

Mike RJS

On 8/22/2005 7:40 PM Busahaulic wrote:

> Sounds good to me. I don't know about your solution, but if the bolts
> tighten up afterwards, why not? You may have to finish it wet sanding on a
> piece of flat glass (with wet/dry paper of course) I do that in the sink
> with water trickling continuously. (It must be perfectly flat and the two
> surfaces must be somewhere close to parallel.)
> -BaH
> "Mike Rocket J. Squirrel Elliott"
> m> wrote in message
> ...
>
>>I'll be darned. I guess this diagnostic limb I went out on was strong
>>enough to hold me without breaking: the reason the Wonderbus's engine is
>>dying when the car is braking or sitting with the nose lower than the
>>rear does appear to be low fuel pressure, like I guessed.
>>
>>For single-carb engines, Bentley's says we want 3 to 5 psi. The pump is
>>putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
>>the front of the bus, away from the pump and I guess the pump does not
>>have sufficient sucking power to keep it, er, up.
>>
>>Next step: identify the cause of the low pressure. The bus accelerates
>>and cruises normally, so I don't think I have a restriction anywhere.
>>Bentley's says that the pump pushrod is supposed to extend 13mm (.511'')
>>beyond the upper face of the Intermediate Flange (Bentley's Type 2, Fig
>>4-3) at its maximum extension for proper pump operation. Mine's at
>>12.1mm (.476'') maximum. That's with NO gaskets between the Intermediate
>>Flange and the engine.
>>
>>I recall reading someplace that one way to lengthen the rod is to weld a
>>little bead on the end and polish it . . . but I don't weld.
>>
>>I do, however, have a belt sander. How about taking a little off the top
>>of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
>>
>>More better would probably be to buy a new pushrod . . . but what kind
>>of fuel pump does this engine have. Single-carb 1600 DP, so it is not a
>>side-mount. It does NOT exactly match up with any of the illustrations
>>in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
>>not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
>>pump. And it's not the Fig 4-4 pump.
>>
>>While the pump is out, I'll disassemble it and clean it and look for
>>problems there.
>>
>>Am I sorta/kinda on the right track to solving this problem? Is the belt
>>sander Intermediate Flange modification, like, really stupid?
>>
>>--
>>Mike Rocket J. Squirrel Elliott
>>
>>
>>
>>On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
>>
>>
>>>Hi all,
>>>
>>>I've been away for a while, enjoying the Wonderbus, and out camping in
>>>our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
>>>outfitting with low-power lighting, and solar panels. That way, Mrs
>>>Squirrel has a cozy and happy little home to camp in which makes her
>>>happy. A happy Mrs Squirrel means I get to camp more. And I love
>
> camping.
>
>>>But enough about that. A problem has surfaced in the 71 Wonderbus. It
>>>started out as an occasional thing a week or so ago, but it now happens
>>>all the time.
>>>
>>>After cruising at speed for a little bit (several seconds, a few
>>>minutes, a while on the freeway, along a city street . . . just normal
>>>driving), the engine stalls when I put in the clutch. This will occur
>>>when I hit the freeway offramp, or just pull up to a stop sign. If I can
>>>use the e-brake to stop and keep the foot on the gas and keep the rpm's
>>>up above a thousand or so, it gets over it and will idle just fine when
>>>I take the foot off the gas.
>>>
>>>Once it dies, I can easily re-start it. There are no problem while
>>>driving. Repeat: no problems while driving once the engine has
>>>re-started. It idles fine, it drives fine. It's only after driving and
>>>when the foot goes off the gas that the engine dies.
>>>
>>>I notice that it also likes to die when the nose is downhill and the
>>>engine is idling . . . like waiting on a downhill street and waiting for
>>>a light to change or something.
>>>
>>>I am going out on a diagnostic limb here (applying all my tiny rodent
>>>brain cells and my minuscule experience and understanding of how The
>>>Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
>>>deceleration and nose-downhill conditions pull gas forward toward the
>>>tank. If the pump is wimping out, it might starve the engine. Clue 2:
>>>This is an older fuel pump that I took off the Wonderbus's failed 1776
>>>engine and installed on the new Mexican Type 1 1600DP engine earlier
>>>this year (or late last year, I forget). Anyway, when I was putting the
>>>fuel pump on, I measured the throw of the rod that pushes on the pump's
>>>diaphragm and it was almost less than the low side of the length
>>>tolerance. Clue 3. At that time, I measured fuel pressure and it also
>>>was on the low side. So I am voting for low fuel pressure as the cause
>>>of this exciting new behavior.
>>>
>>>Tomorrow I will tap into the output of the fuel pump and measure the
>>>pressure.
>>>
>>>While I am at it, I'd like to hear if anyone has any other good ideas of
>>>what I might check into?
>>>
>>>Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
>>>aircooled.net), CDI, SVDA dizzie.
>>
>>
>>--
>>
>>Mike "Rocket J Squirrel" Elliott
>>71 Type 2: the Wonderbus
>>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>KG6RCR
>
>
>


--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR

Okay, fuel pump is back on (slightly longer pushrod, but still
disappointingly low 2.8 psi). While idling, there is no effect on rpm's
when brake is applied. On a short drive (to the grocery store -- Mrs
Squirrel wanted me to pick up some mac 'n' cheese for our visiting
grandson) I could not get the brakes to cause the idle rpm's to shift
upward or downward at all.

Except twice. Two time the engine just died when I was braking. Before
those two times, and afterwards, zero brake-engine interaction. But
nothing else seems to cause the engine to die. That said, I can't even
be certain that the brakes are causing the engine to die, or if it was
just waiting for my foot to go off the gas to die.

Either way, the engine started right up again.

Sheesh.

--

Mike RJS

On 8/23/2005 2:02 PM Mike Rocket J. Squirrel Elliott wrote:

> Thanks for the feedback. I think that my diagnosis must be incorrect,
> though. Low fuel pump pressure should not cause the engine to die when
> it is returned to idle. Someone who knows a lot more about these things
> than I ever will e-mailed me to point out that there is enough fuel in
> the carb bowl to let the engine run for a minute or so.
>
> That notwithstanding, I am wanting to get the fuel pressure up to the
> specified 3 to 5 psi range. I hoped that a longer pushrod would do the
> job -- the 110mm rods from Jbugs.com (within driving distance) looked
> perfect. But they actually measure at 106mm, and mine is 105mm. Their
> shorter "100mm" pushrod measures 100mm. Maybe some other vendor, like
> aircooled.net will have a longer pushrod.
>
> Anyhoo, the Smarter Guy suggested that I probably have a vacuum leak in
> the brake booster. This does line up with my experience that the engine
> dies when returned to idle while I am either decelerating, or when the
> bus is sitting nose down at a red light. In both cases, I am using the
> brake.
>
> So I'll paste this thing together and check to see if the engine dying
> is related to brake usage.
>
> --
>
> Mike RJS
>
> On 8/22/2005 7:40 PM Busahaulic wrote:
>
>> Sounds good to me. I don't know about your solution, but if the bolts
>> tighten up afterwards, why not? You may have to finish it wet sanding
>> on a
>> piece of flat glass (with wet/dry paper of course) I do that in the sink
>> with water trickling continuously. (It must be perfectly flat and the two
>> surfaces must be somewhere close to parallel.)
>> -BaH
>> "Mike Rocket J. Squirrel Elliott"
>> m> wrote in message
>> ...
>>
>>> I'll be darned. I guess this diagnostic limb I went out on was strong
>>> enough to hold me without breaking: the reason the Wonderbus's engine is
>>> dying when the car is braking or sitting with the nose lower than the
>>> rear does appear to be low fuel pressure, like I guessed.
>>>
>>> For single-carb engines, Bentley's says we want 3 to 5 psi. The pump is
>>> putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
>>> the front of the bus, away from the pump and I guess the pump does not
>>> have sufficient sucking power to keep it, er, up.
>>>
>>> Next step: identify the cause of the low pressure. The bus accelerates
>>> and cruises normally, so I don't think I have a restriction anywhere.
>>> Bentley's says that the pump pushrod is supposed to extend 13mm (.511'')
>>> beyond the upper face of the Intermediate Flange (Bentley's Type 2, Fig
>>> 4-3) at its maximum extension for proper pump operation. Mine's at
>>> 12.1mm (.476'') maximum. That's with NO gaskets between the Intermediate
>>> Flange and the engine.
>>>
>>> I recall reading someplace that one way to lengthen the rod is to weld a
>>> little bead on the end and polish it . . . but I don't weld.
>>>
>>> I do, however, have a belt sander. How about taking a little off the top
>>> of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
>>>
>>> More better would probably be to buy a new pushrod . . . but what kind
>>> of fuel pump does this engine have. Single-carb 1600 DP, so it is not a
>>> side-mount. It does NOT exactly match up with any of the illustrations
>>> in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
>>> not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
>>> pump. And it's not the Fig 4-4 pump.
>>>
>>> While the pump is out, I'll disassemble it and clean it and look for
>>> problems there.
>>>
>>> Am I sorta/kinda on the right track to solving this problem? Is the belt
>>> sander Intermediate Flange modification, like, really stupid?
>>>
>>> --
>>> Mike Rocket J. Squirrel Elliott
>>>
>>>
>>>
>>> On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
>>>
>>>
>>>> Hi all,
>>>>
>>>> I've been away for a while, enjoying the Wonderbus, and out camping in
>>>> our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
>>>> outfitting with low-power lighting, and solar panels. That way, Mrs
>>>> Squirrel has a cozy and happy little home to camp in which makes her
>>>> happy. A happy Mrs Squirrel means I get to camp more. And I love
>>
>>
>> camping.
>>
>>>> But enough about that. A problem has surfaced in the 71 Wonderbus. It
>>>> started out as an occasional thing a week or so ago, but it now happens
>>>> all the time.
>>>>
>>>> After cruising at speed for a little bit (several seconds, a few
>>>> minutes, a while on the freeway, along a city street . . . just normal
>>>> driving), the engine stalls when I put in the clutch. This will occur
>>>> when I hit the freeway offramp, or just pull up to a stop sign. If I
>>>> can
>>>> use the e-brake to stop and keep the foot on the gas and keep the rpm's
>>>> up above a thousand or so, it gets over it and will idle just fine when
>>>> I take the foot off the gas.
>>>>
>>>> Once it dies, I can easily re-start it. There are no problem while
>>>> driving. Repeat: no problems while driving once the engine has
>>>> re-started. It idles fine, it drives fine. It's only after driving and
>>>> when the foot goes off the gas that the engine dies.
>>>>
>>>> I notice that it also likes to die when the nose is downhill and the
>>>> engine is idling . . . like waiting on a downhill street and waiting
>>>> for
>>>> a light to change or something.
>>>>
>>>> I am going out on a diagnostic limb here (applying all my tiny rodent
>>>> brain cells and my minuscule experience and understanding of how The
>>>> Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
>>>> deceleration and nose-downhill conditions pull gas forward toward the
>>>> tank. If the pump is wimping out, it might starve the engine. Clue 2:
>>>> This is an older fuel pump that I took off the Wonderbus's failed 1776
>>>> engine and installed on the new Mexican Type 1 1600DP engine earlier
>>>> this year (or late last year, I forget). Anyway, when I was putting the
>>>> fuel pump on, I measured the throw of the rod that pushes on the pump's
>>>> diaphragm and it was almost less than the low side of the length
>>>> tolerance. Clue 3. At that time, I measured fuel pressure and it also
>>>> was on the low side. So I am voting for low fuel pressure as the cause
>>>> of this exciting new behavior.
>>>>
>>>> Tomorrow I will tap into the output of the fuel pump and measure the
>>>> pressure.
>>>>
>>>> While I am at it, I'd like to hear if anyone has any other good
>>>> ideas of
>>>> what I might check into?
>>>>
>>>> Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1 from
>>>> aircooled.net), CDI, SVDA dizzie.
>>>
>>>
>>>
>>> --
>>>
>>> Mike "Rocket J Squirrel" Elliott
>>> 71 Type 2: the Wonderbus
>>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>> KG6RCR
>>
>>
>>
>>
>
>


--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR

You're running a Pertronix ignitor, right? Try a vacuum pump on the
diaphragm while running. Pump it up, release it, etcetera. See if there is
any missing or cut out related to rotation of the breaker plate (vacuum
advance.) If so, look for a wire shorting or a wire being bent sharply as it
exits the little black box (I'm picking right up on that electronic jargon
aren't I!) Or a grounding problem. I had one with which the wire was being
bent sharply as it exited the housing which caused the strands inside the
insulation to break even though the soft insulation was still perfect.
Anther common one is the grounding wire that keeps the breaker plate
grounded, breaking.

Another diagnostic tool: If you have a timing light that doesn't require
house current, hook it up to the coil and position the light such that you
can see it in the rear view mirror. When the motor conks, glance in the
mirror and see if it's still flashing. That way you'll see if it is fuel
related or ignition related. (Your bus has a top hatch in the engine
compartment doesn't it?)

You're right about the fuel-in-the-floatbowl situation.

I wonder how your check valve is on the vacuum line to the brake servo.
Maybe it's sticking intermitently?

Good to see ya back even if it's for a problem! -BaH
"Mike Rocket J. Squirrel Elliott"
m> wrote in message
...
> Okay, fuel pump is back on (slightly longer pushrod, but still
> disappointingly low 2.8 psi). While idling, there is no effect on rpm's
> when brake is applied. On a short drive (to the grocery store -- Mrs
> Squirrel wanted me to pick up some mac 'n' cheese for our visiting
> grandson) I could not get the brakes to cause the idle rpm's to shift
> upward or downward at all.
>
> Except twice. Two time the engine just died when I was braking. Before
> those two times, and afterwards, zero brake-engine interaction. But
> nothing else seems to cause the engine to die. That said, I can't even
> be certain that the brakes are causing the engine to die, or if it was
> just waiting for my foot to go off the gas to die.
>
> Either way, the engine started right up again.
>
> Sheesh.
>
> --
>
> Mike RJS
>
> On 8/23/2005 2:02 PM Mike Rocket J. Squirrel Elliott wrote:
>
> > Thanks for the feedback. I think that my diagnosis must be incorrect,
> > though. Low fuel pump pressure should not cause the engine to die when
> > it is returned to idle. Someone who knows a lot more about these things
> > than I ever will e-mailed me to point out that there is enough fuel in
> > the carb bowl to let the engine run for a minute or so.
> >
> > That notwithstanding, I am wanting to get the fuel pressure up to the
> > specified 3 to 5 psi range. I hoped that a longer pushrod would do the
> > job -- the 110mm rods from Jbugs.com (within driving distance) looked
> > perfect. But they actually measure at 106mm, and mine is 105mm. Their
> > shorter "100mm" pushrod measures 100mm. Maybe some other vendor, like
> > aircooled.net will have a longer pushrod.
> >
> > Anyhoo, the Smarter Guy suggested that I probably have a vacuum leak in
> > the brake booster. This does line up with my experience that the engine
> > dies when returned to idle while I am either decelerating, or when the
> > bus is sitting nose down at a red light. In both cases, I am using the
> > brake.
> >
> > So I'll paste this thing together and check to see if the engine dying
> > is related to brake usage.
> >
> > --
> >
> > Mike RJS
> >
> > On 8/22/2005 7:40 PM Busahaulic wrote:
> >
> >> Sounds good to me. I don't know about your solution, but if the bolts
> >> tighten up afterwards, why not? You may have to finish it wet sanding
> >> on a
> >> piece of flat glass (with wet/dry paper of course) I do that in the
sink
> >> with water trickling continuously. (It must be perfectly flat and the
two
> >> surfaces must be somewhere close to parallel.)
> >> -BaH
> >> "Mike Rocket J. Squirrel Elliott"
> >> m> wrote in message
> >> ...
> >>
> >>> I'll be darned. I guess this diagnostic limb I went out on was strong
> >>> enough to hold me without breaking: the reason the Wonderbus's engine
is
> >>> dying when the car is braking or sitting with the nose lower than the
> >>> rear does appear to be low fuel pressure, like I guessed.
> >>>
> >>> For single-carb engines, Bentley's says we want 3 to 5 psi. The pump
is
> >>> putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
> >>> the front of the bus, away from the pump and I guess the pump does not
> >>> have sufficient sucking power to keep it, er, up.
> >>>
> >>> Next step: identify the cause of the low pressure. The bus accelerates
> >>> and cruises normally, so I don't think I have a restriction anywhere.
> >>> Bentley's says that the pump pushrod is supposed to extend 13mm
(.511'')
> >>> beyond the upper face of the Intermediate Flange (Bentley's Type 2,
Fig
> >>> 4-3) at its maximum extension for proper pump operation. Mine's at
> >>> 12.1mm (.476'') maximum. That's with NO gaskets between the
Intermediate
> >>> Flange and the engine.
> >>>
> >>> I recall reading someplace that one way to lengthen the rod is to weld
a
> >>> little bead on the end and polish it . . . but I don't weld.
> >>>
> >>> I do, however, have a belt sander. How about taking a little off the
top
> >>> of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
> >>>
> >>> More better would probably be to buy a new pushrod . . . but what kind
> >>> of fuel pump does this engine have. Single-carb 1600 DP, so it is not
a
> >>> side-mount. It does NOT exactly match up with any of the illustrations
> >>> in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
> >>> not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
> >>> pump. And it's not the Fig 4-4 pump.
> >>>
> >>> While the pump is out, I'll disassemble it and clean it and look for
> >>> problems there.
> >>>
> >>> Am I sorta/kinda on the right track to solving this problem? Is the
belt
> >>> sander Intermediate Flange modification, like, really stupid?
> >>>
> >>> --
> >>> Mike Rocket J. Squirrel Elliott
> >>>
> >>>
> >>>
> >>> On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
> >>>
> >>>
> >>>> Hi all,
> >>>>
> >>>> I've been away for a while, enjoying the Wonderbus, and out camping
in
> >>>> our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
> >>>> outfitting with low-power lighting, and solar panels. That way, Mrs
> >>>> Squirrel has a cozy and happy little home to camp in which makes her
> >>>> happy. A happy Mrs Squirrel means I get to camp more. And I love
> >>
> >>
> >> camping.
> >>
> >>>> But enough about that. A problem has surfaced in the 71 Wonderbus. It
> >>>> started out as an occasional thing a week or so ago, but it now
happens
> >>>> all the time.
> >>>>
> >>>> After cruising at speed for a little bit (several seconds, a few
> >>>> minutes, a while on the freeway, along a city street . . . just
normal
> >>>> driving), the engine stalls when I put in the clutch. This will occur
> >>>> when I hit the freeway offramp, or just pull up to a stop sign. If I
> >>>> can
> >>>> use the e-brake to stop and keep the foot on the gas and keep the
rpm's
> >>>> up above a thousand or so, it gets over it and will idle just fine
when
> >>>> I take the foot off the gas.
> >>>>
> >>>> Once it dies, I can easily re-start it. There are no problem while
> >>>> driving. Repeat: no problems while driving once the engine has
> >>>> re-started. It idles fine, it drives fine. It's only after driving
and
> >>>> when the foot goes off the gas that the engine dies.
> >>>>
> >>>> I notice that it also likes to die when the nose is downhill and the
> >>>> engine is idling . . . like waiting on a downhill street and waiting
> >>>> for
> >>>> a light to change or something.
> >>>>
> >>>> I am going out on a diagnostic limb here (applying all my tiny rodent
> >>>> brain cells and my minuscule experience and understanding of how The
> >>>> Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
> >>>> deceleration and nose-downhill conditions pull gas forward toward the
> >>>> tank. If the pump is wimping out, it might starve the engine. Clue 2:
> >>>> This is an older fuel pump that I took off the Wonderbus's failed
1776
> >>>> engine and installed on the new Mexican Type 1 1600DP engine earlier
> >>>> this year (or late last year, I forget). Anyway, when I was putting
the
> >>>> fuel pump on, I measured the throw of the rod that pushes on the
pump's
> >>>> diaphragm and it was almost less than the low side of the length
> >>>> tolerance. Clue 3. At that time, I measured fuel pressure and it also
> >>>> was on the low side. So I am voting for low fuel pressure as the
cause
> >>>> of this exciting new behavior.
> >>>>
> >>>> Tomorrow I will tap into the output of the fuel pump and measure the
> >>>> pressure.
> >>>>
> >>>> While I am at it, I'd like to hear if anyone has any other good
> >>>> ideas of
> >>>> what I might check into?
> >>>>
> >>>> Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1
from
> >>>> aircooled.net), CDI, SVDA dizzie.
> >>>
> >>>
> >>>
> >>> --
> >>>
> >>> Mike "Rocket J Squirrel" Elliott
> >>> 71 Type 2: the Wonderbus
> >>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> >>> KG6RCR
> >>
> >>
> >>
> >>
> >
> >
>
>
> --
>
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> KG6RCR

On 8/23/2005 5:53 PM Busahaulic wrote:

> You're running a Pertronix ignitor, right? Try a vacuum pump on the
> diaphragm while running. Pump it up, release it, etcetera.

Compu-Fire pointless and Tiger CDI. But I am not getting this vacuum
pump on the diaphragm thing. Makes me think of Austin Powers and the
penis enlargement pump . . . but I don't think that's what you are
talking about at all.

> See if there is
> any missing or cut out related to rotation of the breaker plate (vacuum
> advance.) If so, look for a wire shorting or a wire being bent sharply as it
> exits the little black box (I'm picking right up on that electronic jargon
> aren't I!) Or a grounding problem. I had one with which the wire was being
> bent sharply as it exited the housing which caused the strands inside the
> insulation to break even though the soft insulation was still perfect.
> Anther common one is the grounding wire that keeps the breaker plate
> grounded, breaking.

Wait -- I see, you're suggesting I look for a problem with the points
replacement module's wiring. Good idea, though that vacuum pump thing I
have to think about. Maybe I can modify my bike pump? Nah.

>
> Another diagnostic tool: If you have a timing light that doesn't require
> house current, hook it up to the coil and position the light such that you
> can see it in the rear view mirror. When the motor conks, glance in the
> mirror and see if it's still flashing. That way you'll see if it is fuel
> related or ignition related. (Your bus has a top hatch in the engine
> compartment doesn't it?)

Nope. I can figure out how to run the wires from the engine hatch into
the rear of the bus anyway. But, uh, when the engine conks, wouldn't I
pretty much expect there to be no spark? How will the light give me any
information?

> You're right about the fuel-in-the-floatbowl situation.

Yeah, well, if I'd ever rebuilt a carb I probably would have known about
that.

> I wonder how your check valve is on the vacuum line to the brake servo.
> Maybe it's sticking intermitently?

Hm. I reckon the only test for that is to R&R the check valve.

>
> Good to see ya back even if it's for a problem! -BaH

Thanks! And it's nice of you to help!

--
Mike Rocket J. Squirrel Elliott

> "Mike Rocket J. Squirrel Elliott"
> m> wrote in message
> ...
>
>>Okay, fuel pump is back on (slightly longer pushrod, but still
>>disappointingly low 2.8 psi). While idling, there is no effect on rpm's
>>when brake is applied. On a short drive (to the grocery store -- Mrs
>>Squirrel wanted me to pick up some mac 'n' cheese for our visiting
>>grandson) I could not get the brakes to cause the idle rpm's to shift
>>upward or downward at all.
>>
>>Except twice. Two time the engine just died when I was braking. Before
>>those two times, and afterwards, zero brake-engine interaction. But
>>nothing else seems to cause the engine to die. That said, I can't even
>>be certain that the brakes are causing the engine to die, or if it was
>>just waiting for my foot to go off the gas to die.
>>
>>Either way, the engine started right up again.
>>
>>Sheesh.
>>
>>--
>>
>>Mike RJS
>>
>>On 8/23/2005 2:02 PM Mike Rocket J. Squirrel Elliott wrote:
>>
>>
>>>Thanks for the feedback. I think that my diagnosis must be incorrect,
>>>though. Low fuel pump pressure should not cause the engine to die when
>>>it is returned to idle. Someone who knows a lot more about these things
>>>than I ever will e-mailed me to point out that there is enough fuel in
>>>the carb bowl to let the engine run for a minute or so.
>>>
>>>That notwithstanding, I am wanting to get the fuel pressure up to the
>>>specified 3 to 5 psi range. I hoped that a longer pushrod would do the
>>>job -- the 110mm rods from Jbugs.com (within driving distance) looked
>>>perfect. But they actually measure at 106mm, and mine is 105mm. Their
>>>shorter "100mm" pushrod measures 100mm. Maybe some other vendor, like
>>>aircooled.net will have a longer pushrod.
>>>
>>>Anyhoo, the Smarter Guy suggested that I probably have a vacuum leak in
>>>the brake booster. This does line up with my experience that the engine
>>>dies when returned to idle while I am either decelerating, or when the
>>>bus is sitting nose down at a red light. In both cases, I am using the
>>>brake.
>>>
>>>So I'll paste this thing together and check to see if the engine dying
>>>is related to brake usage.
>>>
>>>--
>>>
>>>Mike RJS
>>>
>>>On 8/22/2005 7:40 PM Busahaulic wrote:
>>>
>>>
>>>>Sounds good to me. I don't know about your solution, but if the bolts
>>>>tighten up afterwards, why not? You may have to finish it wet sanding
>>>>on a
>>>>piece of flat glass (with wet/dry paper of course) I do that in the
>
> sink
>
>>>>with water trickling continuously. (It must be perfectly flat and the
>
> two
>
>>>>surfaces must be somewhere close to parallel.)
>>>>-BaH
>>>>"Mike Rocket J. Squirrel Elliott"
>>>><j.michael.elliottAT@REMOVETHEOBVIOUSgmailDOT. com> wrote in message
...
>>>>
>>>>
>>>>>I'll be darned. I guess this diagnostic limb I went out on was strong
>>>>>enough to hold me without breaking: the reason the Wonderbus's engine
>
> is
>
>>>>>dying when the car is braking or sitting with the nose lower than the
>>>>>rear does appear to be low fuel pressure, like I guessed.
>>>>>
>>>>>For single-carb engines, Bentley's says we want 3 to 5 psi. The pump
>
> is
>
>>>>>putting out 2.8 psi. Braking and nose-down conditions pull fuel toward
>>>>>the front of the bus, away from the pump and I guess the pump does not
>>>>>have sufficient sucking power to keep it, er, up.
>>>>>
>>>>>Next step: identify the cause of the low pressure. The bus accelerates
>>>>>and cruises normally, so I don't think I have a restriction anywhere.
>>>>>Bentley's says that the pump pushrod is supposed to extend 13mm
>
> (.511'')
>
>>>>>beyond the upper face of the Intermediate Flange (Bentley's Type 2,
>
> Fig
>
>>>>>4-3) at its maximum extension for proper pump operation. Mine's at
>>>>>12.1mm (.476'') maximum. That's with NO gaskets between the
>
> Intermediate
>
>>>>>Flange and the engine.
>>>>>
>>>>>I recall reading someplace that one way to lengthen the rod is to weld
>
> a
>
>>>>>little bead on the end and polish it . . . but I don't weld.
>>>>>
>>>>>I do, however, have a belt sander. How about taking a little off the
>
> top
>
>>>>>of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
>>>>>
>>>>>More better would probably be to buy a new pushrod . . . but what kind
>>>>>of fuel pump does this engine have. Single-carb 1600 DP, so it is not
>
> a
>
>>>>>side-mount. It does NOT exactly match up with any of the illustrations
>>>>>in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
>>>>>not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
>>>>>pump. And it's not the Fig 4-4 pump.
>>>>>
>>>>>While the pump is out, I'll disassemble it and clean it and look for
>>>>>problems there.
>>>>>
>>>>>Am I sorta/kinda on the right track to solving this problem? Is the
>
> belt
>
>>>>>sander Intermediate Flange modification, like, really stupid?
>>>>>
>>>>>--
>>>>>Mike Rocket J. Squirrel Elliott
>>>>>
>>>>>
>>>>>
>>>>>On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
>>>>>
>>>>>
>>>>>
>>>>>>Hi all,
>>>>>>
>>>>>>I've been away for a while, enjoying the Wonderbus, and out camping
>
> in
>
>>>>>>our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
>>>>>>outfitting with low-power lighting, and solar panels. That way, Mrs
>>>>>>Squirrel has a cozy and happy little home to camp in which makes her
>>>>>>happy. A happy Mrs Squirrel means I get to camp more. And I love
>>>>
>>>>
>>>>camping.
>>>>
>>>>
>>>>>>But enough about that. A problem has surfaced in the 71 Wonderbus. It
>>>>>>started out as an occasional thing a week or so ago, but it now
>
> happens
>
>>>>>>all the time.
>>>>>>
>>>>>>After cruising at speed for a little bit (several seconds, a few
>>>>>>minutes, a while on the freeway, along a city street . . . just
>
> normal
>
>>>>>>driving), the engine stalls when I put in the clutch. This will occur
>>>>>>when I hit the freeway offramp, or just pull up to a stop sign. If I
>>>>>>can
>>>>>>use the e-brake to stop and keep the foot on the gas and keep the
>
> rpm's
>
>>>>>>up above a thousand or so, it gets over it and will idle just fine
>
> when
>
>>>>>>I take the foot off the gas.
>>>>>>
>>>>>>Once it dies, I can easily re-start it. There are no problem while
>>>>>>driving. Repeat: no problems while driving once the engine has
>>>>>>re-started. It idles fine, it drives fine. It's only after driving
>
> and
>
>>>>>>when the foot goes off the gas that the engine dies.
>>>>>>
>>>>>>I notice that it also likes to die when the nose is downhill and the
>>>>>>engine is idling . . . like waiting on a downhill street and waiting
>>>>>>for
>>>>>>a light to change or something.
>>>>>>
>>>>>>I am going out on a diagnostic limb here (applying all my tiny rodent
>>>>>>brain cells and my minuscule experience and understanding of how The
>>>>>>Wonderbus works): I think it is a fuel pressure problem. Clue 1: Both
>>>>>>deceleration and nose-downhill conditions pull gas forward toward the
>>>>>>tank. If the pump is wimping out, it might starve the engine. Clue 2:
>>>>>>This is an older fuel pump that I took off the Wonderbus's failed
>
> 1776
>
>>>>>>engine and installed on the new Mexican Type 1 1600DP engine earlier
>>>>>>this year (or late last year, I forget). Anyway, when I was putting
>
> the
>
>>>>>>fuel pump on, I measured the throw of the rod that pushes on the
>
> pump's
>
>>>>>>diaphragm and it was almost less than the low side of the length
>>>>>>tolerance. Clue 3. At that time, I measured fuel pressure and it also
>>>>>>was on the low side. So I am voting for low fuel pressure as the
>
> cause
>
>>>>>>of this exciting new behavior.
>>>>>>
>>>>>>Tomorrow I will tap into the output of the fuel pump and measure the
>>>>>>pressure.
>>>>>>
>>>>>>While I am at it, I'd like to hear if anyone has any other good
>>>>>>ideas of
>>>>>>what I might check into?
>>>>>>
>>>>>>Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1
>
> from
>
>>>>>>aircooled.net), CDI, SVDA dizzie.
>>>>>
>>>>>
>>>>>
>>>>>--
>>>>>
>>>>>Mike "Rocket J Squirrel" Elliott
>>>>>71 Type 2: the Wonderbus
>>>>>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>>>>KG6RCR
>>>>
>>>>
>>>>
>>>>
>>>
>>
>>--
>>
>>Mike "Rocket J Squirrel" Elliott
>>71 Type 2: the Wonderbus
>>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>KG6RCR
>
>
>


--

Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
KG6RCR

The vacuum diaphragm operates a lever attached to the plate the breaker
points are mounted on (until you remove them and insert CompuFire!) The
movement of that plate (rotational) is what retards the timing on a pull
(low vacuum) and advances it when engine's not working so hard (high
vacuum). It is not uncommon for there to be intermitent open circuit
problems for various reasons (as I mentioned earlier) while that plate
rotates.

The light will keep flashing until the engine stops turning which is likely
several seconds after it cuts out. Perhaps "conks" was improper use of the
phraseology. If the engine cuts out and you look in the mirror and the light
has stopped flashing, you can bet on one of two things: The problem is not
fuel (OR) You didn't look quickly enough and the engine had stopped
rotating! (Unlikely)

Didn't you put a new check valve in when you installed the new engine? I
seem to recall that you were having trouble with the brakes and that the
servo was disconnected and that you reconnected it - or am I thinking of a
raccoon of a similar name or perhaps a possum?
-BaH
"Mike Rocket J. Squirrel Elliott"
m> wrote in message
...
> On 8/23/2005 5:53 PM Busahaulic wrote:
>
> > You're running a Pertronix ignitor, right? Try a vacuum pump on the
> > diaphragm while running. Pump it up, release it, etcetera.
>
> Compu-Fire pointless and Tiger CDI. But I am not getting this vacuum
> pump on the diaphragm thing. Makes me think of Austin Powers and the
> penis enlargement pump . . . but I don't think that's what you are
> talking about at all.
>
> > See if there is
> > any missing or cut out related to rotation of the breaker plate (vacuum
> > advance.) If so, look for a wire shorting or a wire being bent sharply
as it
> > exits the little black box (I'm picking right up on that electronic
jargon
> > aren't I!) Or a grounding problem. I had one with which the wire was
being
> > bent sharply as it exited the housing which caused the strands inside
the
> > insulation to break even though the soft insulation was still perfect.
> > Anther common one is the grounding wire that keeps the breaker plate
> > grounded, breaking.
>
> Wait -- I see, you're suggesting I look for a problem with the points
> replacement module's wiring. Good idea, though that vacuum pump thing I
> have to think about. Maybe I can modify my bike pump? Nah.
>
> >
> > Another diagnostic tool: If you have a timing light that doesn't require
> > house current, hook it up to the coil and position the light such that
you
> > can see it in the rear view mirror. When the motor conks, glance in the
> > mirror and see if it's still flashing. That way you'll see if it is fuel
> > related or ignition related. (Your bus has a top hatch in the engine
> > compartment doesn't it?)
>
> Nope. I can figure out how to run the wires from the engine hatch into
> the rear of the bus anyway. But, uh, when the engine conks, wouldn't I
> pretty much expect there to be no spark? How will the light give me any
> information?
>
> > You're right about the fuel-in-the-floatbowl situation.
>
> Yeah, well, if I'd ever rebuilt a carb I probably would have known about
> that.
>
> > I wonder how your check valve is on the vacuum line to the brake servo.
> > Maybe it's sticking intermitently?
>
> Hm. I reckon the only test for that is to R&R the check valve.
>
> >
> > Good to see ya back even if it's for a problem! -BaH
>
> Thanks! And it's nice of you to help!
>
> --
> Mike Rocket J. Squirrel Elliott
>
> > "Mike Rocket J. Squirrel Elliott"
> > m> wrote in message
> > ...
> >
> >>Okay, fuel pump is back on (slightly longer pushrod, but still
> >>disappointingly low 2.8 psi). While idling, there is no effect on rpm's
> >>when brake is applied. On a short drive (to the grocery store -- Mrs
> >>Squirrel wanted me to pick up some mac 'n' cheese for our visiting
> >>grandson) I could not get the brakes to cause the idle rpm's to shift
> >>upward or downward at all.
> >>
> >>Except twice. Two time the engine just died when I was braking. Before
> >>those two times, and afterwards, zero brake-engine interaction. But
> >>nothing else seems to cause the engine to die. That said, I can't even
> >>be certain that the brakes are causing the engine to die, or if it was
> >>just waiting for my foot to go off the gas to die.
> >>
> >>Either way, the engine started right up again.
> >>
> >>Sheesh.
> >>
> >>--
> >>
> >>Mike RJS
> >>
> >>On 8/23/2005 2:02 PM Mike Rocket J. Squirrel Elliott wrote:
> >>
> >>
> >>>Thanks for the feedback. I think that my diagnosis must be incorrect,
> >>>though. Low fuel pump pressure should not cause the engine to die when
> >>>it is returned to idle. Someone who knows a lot more about these things
> >>>than I ever will e-mailed me to point out that there is enough fuel in
> >>>the carb bowl to let the engine run for a minute or so.
> >>>
> >>>That notwithstanding, I am wanting to get the fuel pressure up to the
> >>>specified 3 to 5 psi range. I hoped that a longer pushrod would do the
> >>>job -- the 110mm rods from Jbugs.com (within driving distance) looked
> >>>perfect. But they actually measure at 106mm, and mine is 105mm. Their
> >>>shorter "100mm" pushrod measures 100mm. Maybe some other vendor, like
> >>>aircooled.net will have a longer pushrod.
> >>>
> >>>Anyhoo, the Smarter Guy suggested that I probably have a vacuum leak in
> >>>the brake booster. This does line up with my experience that the engine
> >>>dies when returned to idle while I am either decelerating, or when the
> >>>bus is sitting nose down at a red light. In both cases, I am using the
> >>>brake.
> >>>
> >>>So I'll paste this thing together and check to see if the engine dying
> >>>is related to brake usage.
> >>>
> >>>--
> >>>
> >>>Mike RJS
> >>>
> >>>On 8/22/2005 7:40 PM Busahaulic wrote:
> >>>
> >>>
> >>>>Sounds good to me. I don't know about your solution, but if the bolts
> >>>>tighten up afterwards, why not? You may have to finish it wet sanding
> >>>>on a
> >>>>piece of flat glass (with wet/dry paper of course) I do that in the
> >
> > sink
> >
> >>>>with water trickling continuously. (It must be perfectly flat and the
> >
> > two
> >
> >>>>surfaces must be somewhere close to parallel.)
> >>>>-BaH
> >>>>"Mike Rocket J. Squirrel Elliott"
> >>>><j.michael.elliottAT@REMOVETHEOBVIOUSgmailDOT. com> wrote in message
> ...
> >>>>
> >>>>
> >>>>>I'll be darned. I guess this diagnostic limb I went out on was strong
> >>>>>enough to hold me without breaking: the reason the Wonderbus's engine
> >
> > is
> >
> >>>>>dying when the car is braking or sitting with the nose lower than the
> >>>>>rear does appear to be low fuel pressure, like I guessed.
> >>>>>
> >>>>>For single-carb engines, Bentley's says we want 3 to 5 psi. The pump
> >
> > is
> >
> >>>>>putting out 2.8 psi. Braking and nose-down conditions pull fuel
toward
> >>>>>the front of the bus, away from the pump and I guess the pump does
not
> >>>>>have sufficient sucking power to keep it, er, up.
> >>>>>
> >>>>>Next step: identify the cause of the low pressure. The bus
accelerates
> >>>>>and cruises normally, so I don't think I have a restriction anywhere.
> >>>>>Bentley's says that the pump pushrod is supposed to extend 13mm
> >
> > (.511'')
> >
> >>>>>beyond the upper face of the Intermediate Flange (Bentley's Type 2,
> >
> > Fig
> >
> >>>>>4-3) at its maximum extension for proper pump operation. Mine's at
> >>>>>12.1mm (.476'') maximum. That's with NO gaskets between the
> >
> > Intermediate
> >
> >>>>>Flange and the engine.
> >>>>>
> >>>>>I recall reading someplace that one way to lengthen the rod is to
weld
> >
> > a
> >
> >>>>>little bead on the end and polish it . . . but I don't weld.
> >>>>>
> >>>>>I do, however, have a belt sander. How about taking a little off the
> >
> > top
> >
> >>>>>of the Intermediate Flange? (Bentley's Type 2, Fig 4-3).
> >>>>>
> >>>>>More better would probably be to buy a new pushrod . . . but what
kind
> >>>>>of fuel pump does this engine have. Single-carb 1600 DP, so it is not
> >
> > a
> >
> >>>>>side-mount. It does NOT exactly match up with any of the
illustrations
> >>>>>in Bentleys. It mounts on top of the engine like Fig 4-3, but it does
> >>>>>not look like Fig 4-3 . . . the top has four bolts like the 4-2 fuel
> >>>>>pump. And it's not the Fig 4-4 pump.
> >>>>>
> >>>>>While the pump is out, I'll disassemble it and clean it and look for
> >>>>>problems there.
> >>>>>
> >>>>>Am I sorta/kinda on the right track to solving this problem? Is the
> >
> > belt
> >
> >>>>>sander Intermediate Flange modification, like, really stupid?
> >>>>>
> >>>>>--
> >>>>>Mike Rocket J. Squirrel Elliott
> >>>>>
> >>>>>
> >>>>>
> >>>>>On 8/21/2005 5:35 PM Mike Rocket J. Squirrel Elliott wrote:
> >>>>>
> >>>>>
> >>>>>
> >>>>>>Hi all,
> >>>>>>
> >>>>>>I've been away for a while, enjoying the Wonderbus, and out camping
> >
> > in
> >
> >>>>>>our 84 water-cooled (evil, hiss hiss) Vanagon while I have been
> >>>>>>outfitting with low-power lighting, and solar panels. That way, Mrs
> >>>>>>Squirrel has a cozy and happy little home to camp in which makes her
> >>>>>>happy. A happy Mrs Squirrel means I get to camp more. And I love
> >>>>
> >>>>
> >>>>camping.
> >>>>
> >>>>
> >>>>>>But enough about that. A problem has surfaced in the 71 Wonderbus.
It
> >>>>>>started out as an occasional thing a week or so ago, but it now
> >
> > happens
> >
> >>>>>>all the time.
> >>>>>>
> >>>>>>After cruising at speed for a little bit (several seconds, a few
> >>>>>>minutes, a while on the freeway, along a city street . . . just
> >
> > normal
> >
> >>>>>>driving), the engine stalls when I put in the clutch. This will
occur
> >>>>>>when I hit the freeway offramp, or just pull up to a stop sign. If I
> >>>>>>can
> >>>>>>use the e-brake to stop and keep the foot on the gas and keep the
> >
> > rpm's
> >
> >>>>>>up above a thousand or so, it gets over it and will idle just fine
> >
> > when
> >
> >>>>>>I take the foot off the gas.
> >>>>>>
> >>>>>>Once it dies, I can easily re-start it. There are no problem while
> >>>>>>driving. Repeat: no problems while driving once the engine has
> >>>>>>re-started. It idles fine, it drives fine. It's only after driving
> >
> > and
> >
> >>>>>>when the foot goes off the gas that the engine dies.
> >>>>>>
> >>>>>>I notice that it also likes to die when the nose is downhill and the
> >>>>>>engine is idling . . . like waiting on a downhill street and waiting
> >>>>>>for
> >>>>>>a light to change or something.
> >>>>>>
> >>>>>>I am going out on a diagnostic limb here (applying all my tiny
rodent
> >>>>>>brain cells and my minuscule experience and understanding of how The
> >>>>>>Wonderbus works): I think it is a fuel pressure problem. Clue 1:
Both
> >>>>>>deceleration and nose-downhill conditions pull gas forward toward
the
> >>>>>>tank. If the pump is wimping out, it might starve the engine. Clue
2:
> >>>>>>This is an older fuel pump that I took off the Wonderbus's failed
> >
> > 1776
> >
> >>>>>>engine and installed on the new Mexican Type 1 1600DP engine earlier
> >>>>>>this year (or late last year, I forget). Anyway, when I was putting
> >
> > the
> >
> >>>>>>fuel pump on, I measured the throw of the rod that pushes on the
> >
> > pump's
> >
> >>>>>>diaphragm and it was almost less than the low side of the length
> >>>>>>tolerance. Clue 3. At that time, I measured fuel pressure and it
also
> >>>>>>was on the low side. So I am voting for low fuel pressure as the
> >
> > cause
> >
> >>>>>>of this exciting new behavior.
> >>>>>>
> >>>>>>Tomorrow I will tap into the output of the fuel pump and measure the
> >>>>>>pressure.
> >>>>>>
> >>>>>>While I am at it, I'd like to hear if anyone has any other good
> >>>>>>ideas of
> >>>>>>what I might check into?
> >>>>>>
> >>>>>>Stock 71 bus oil bath filter . . . stock carburetor (new 34 PICT 1
> >
> > from
> >
> >>>>>>aircooled.net), CDI, SVDA dizzie.
> >>>>>
> >>>>>
> >>>>>
> >>>>>--
> >>>>>
> >>>>>Mike "Rocket J Squirrel" Elliott
> >>>>>71 Type 2: the Wonderbus
> >>>>>84 Westfalia: Mellow Yellow ("The Electrical Banana")
> >>>>>KG6RCR
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>
> >>--
> >>
> >>Mike "Rocket J Squirrel" Elliott
> >>71 Type 2: the Wonderbus
> >>84 Westfalia: Mellow Yellow ("The Electrical Banana")
> >>KG6RCR
> >
> >
> >
>
>
> --
>
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> KG6RCR

One more vewwy important item: Try running the CDI on bypass mode - If yours
is as mine was, you simply turn the plug over and it bypasses the CDI and
runs your conventional ignition. Might as well try to eliminate the item
that is most likely to fail right at the start! -BaH