GM OBD1 and no O2 codes?

Nate Nagel wrote:
> Mike Romain wrote:
>> ray wrote:
>>
>>> My 2 cents - if it's not tossing a code, you're going to have to go
>>> back to basics with regards to diagnostics.
>>
>>
>> Yup, guess so.
>>
>>>
>>> Does it do it hot/cold/both?
>>
>>
>> Both
>>
>>> Does it do it at idle/full throttle/both?
>>
>>
>> Both
>>
>>> If you pull the front plugs, do they all look the same? Could be a
>>> bad coil?
>>
>>
>> Good guess! Plug #3 is gas soaked, the other two show normal burn.
>>
>> It is a 3300 engine with a new O2 by the way.
>>
>>> If you know someone with a Tech 1, there is a way to scan them, but I
>>> don't have an OBD1 scan tool... so I read through the manual and
>>> trusted my gut. Maybe try a junkyard 02 sensor - almost free and if
>>> it works then you'll have found your problem.
>>>
>>> Ray
>>
>>
>> Thanks Ray.
>>
>> Mike
>
> O2 sensor will cause all rich or all lean, if you have one plug soaked
> and others not look elsewhere for your problem. If you've been running
> with a dead hole for any length of time you may have a clogged cat,
> which would explain the old O2 blowing out.
>
> nate
>

Argg, well it seemed like a dead plug, not a coil pack, found that one
(#3) with infinity on the ohm meter from the core to the wire clip. Put
in new plug, no joy. grrr.

Can a coil pack fail on one leg only?

One plug wire only fails my induction timing light. New plug and old
plug the same. That plug is gas soaked so it would seem the injector is
working.

I swapped spark plug wires also with the same result, a #3 failure.

The old O2 sensor literally rotted away, it didn't need any back
pressure to blow out. LOL!

Cat shouldn't be plugged, the vehicle will still run with power at 120+
kph. It just doesn't like the 'cusp' where the shift points are so it
doesn't like OD at 100 kph or even D at 60 kph.

It has an even miss all the way up the throttle band.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

Steve B. wrote:
> On Sun, 18 May 2008 12:20:41 -0400, Mike Romain >
> wrote:
>
>> We have a 1990 Cutlass Ciera that blew out the O2 sensor and went into
>> limp home mode. The sensor physically blew out from rust.
>
> The term limp home mode is commonly used for transmission problems.
> When a transmission is in limp home mode it stays in second gear.
> Your O2 sensor would not cause this.
>
>> So I put a new Bosch one in and at about 500 km later, it starts acting
>> exactly the same, with a miss all the way up the throttle and basically
>> no top gear or bad shakes in top gear, just like last time.
>>
>
> Bosch oxygen sensors are total crap. If you feel the problem is still
> oxygen sensor related replace it with a decent part, but that does not
> sound like an oxygen sensor problem from here. Since the old one
> "blew out" I would start by looking for problems with back pressure in
> the exhaust. Perhaps the cat is clogged.
>
>
>> I decided to get the codes to see if maybe something else has gone bad,
>> and after reading '12' three times, no more codes came up.
>>
>> The question is should the bad O2 give a code and/or any other
>> suggestions for a no code miss?
>>
>
> A bad O2 sensor can set a code but it has to be pretty far out to do
> so on that car. The computer is more primitive than what you would
> find on a new car... It doesn't have a before and after the cat O2
> sensor and it does not watch for a miss.
>
> Check the plugs and wires again. Just because something is new
> doesn't mean it is good especially if you are using cheap parts. Have
> the exhaust checked for back pressure issues. Check fuel filter and
> fuel pressure.
>
> Steve B.

Found a dead plug which I replaced.

Still no spark to #3 cylinder. All the rest show spark with my
induction timing light.

Swapped wires. Same miss.

Plug is gas soaked so injector should be working?

Can a coil pack fail on one leg?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

ray wrote:
> Mike Romain wrote:
>> We have a 1990 Cutlass Ciera that blew out the O2 sensor and went into
>> limp home mode. The sensor physically blew out from rust.
>>
>
> btw, which motor? I have the GM shop manual for the Beretta, so if you
> have a motor which was in the Beretta (2.2 or 3.1) I might be able to
> give you some useful hints from the manual on what to check.
>
> Ray

It is the 3300 engine.

I found a gas soaked plug that was actually dead according to the ohm
meter. Put in new plug, still no spark.

Swapped wires, still no spark.

Plug is gas soaked.

The other leg of the coil pack shows spark.

can one leg of the pack go bad?

Do you maybe have the meter readings to test the coil pack?

I need to get a book for this old thing I guess.

Thanks,

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

aarcuda69062 wrote:
>
>> It does 'miss' at idle and all the way up though.
>
> These vehicles were lousy for injector problems, lousy for ignition
> problems, both of which as you probably know will cause a cat-con to
> plug.

I found a wet spark plug. #3

Changed it, same miss and no spark showing on my induction light.

Swapped wires, same deal.

All the rest of the wires show spark on my timing light.

Coil dead on one leg?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
'New' frame in the works for '08. Some Canadian Bush Trip and Build
Photos: http://mikeromainjeeptrips.shutterfly.com

Mike Romain wrote:

>
> Found a dead plug which I replaced.
>
> Still no spark to #3 cylinder. All the rest show spark with my
> induction timing light.

Bad coil pack.

>
> Swapped wires. Same miss.
>
> Plug is gas soaked so injector should be working?

Yep, hard for gas to get there if the injector isn't working.

>
> Can a coil pack fail on one leg?

Yes.


>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
> Photos: http://mikeromainjeeptrips.shutterfly.com


--
Steve W.
Near Cooperstown, New York

Life is not like a box of chocolates
it's more like a jar of jalapenos-
what you do today could burn your ass tomorrow!


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Steve W. wrote:
>
>>
>> Can a coil pack fail on one leg?
>
> Yes.
>
>

I guess the next dumb question from a backyard mechanic who 'really,
really' wants to drive 250 km 'tomorrow' on a holiday Monday up here in
Canada to get to a cottage for a few weeks vacation with my wife would
be can I hot wire the sucker to the other coil HT post and get away with
it? LOL!


>>
>> Mike
>> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
>> 'New' frame in the works for '08. Some Canadian Bush Trip and Build
>> Photos: http://mikeromainjeeptrips.shutterfly.com
>
>

Mike Romain > wrote:
>
>I guess the next dumb question from a backyard mechanic who 'really,
>really' wants to drive 250 km 'tomorrow' on a holiday Monday up here in
>Canada to get to a cottage for a few weeks vacation with my wife would
>be can I hot wire the sucker to the other coil HT post and get away with
>it? LOL!

Then you really WILL blow your muffler off.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:
> Mike Romain > wrote:
>
>>I guess the next dumb question from a backyard mechanic who 'really,
>>really' wants to drive 250 km 'tomorrow' on a holiday Monday up here in
>>Canada to get to a cottage for a few weeks vacation with my wife would
>>be can I hot wire the sucker to the other coil HT post and get away with
>>it? LOL!
>
>
> Then you really WILL blow your muffler off.
> --scott
>

well... not if it is a waste spark ignition system and he connects the
wire to the other cylinder in that pair.

Keep in mind that this is assuming a whole lot of stuff about this
particular car that I don't know for sure.

nate

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Nate Nagel wrote:
> Scott Dorsey wrote:
>> Mike Romain > wrote:
>>
>>> I guess the next dumb question from a backyard mechanic who 'really,
>>> really' wants to drive 250 km 'tomorrow' on a holiday Monday up here
>>> in Canada to get to a cottage for a few weeks vacation with my wife
>>> would be can I hot wire the sucker to the other coil HT post and get
>>> away with it? LOL!
>>
>>
>> Then you really WILL blow your muffler off.
>> --scott
>>
>
> well... not if it is a waste spark ignition system and he connects the
> wire to the other cylinder in that pair.
>
> Keep in mind that this is assuming a whole lot of stuff about this
> particular car that I don't know for sure.
>
> nate
>
It is a 3300 Olds engine with 3 coil packs for 6 cylinders. The HT
wires are on one side of each coil pack.

I guess I need two timing lights to see if both fire at once on one of
the good coil packs.

Mike

Mike Romain wrote:
> Nate Nagel wrote:
>
>> Scott Dorsey wrote:
>>
>>> Mike Romain > wrote:
>>>
>>>> I guess the next dumb question from a backyard mechanic who 'really,
>>>> really' wants to drive 250 km 'tomorrow' on a holiday Monday up here
>>>> in Canada to get to a cottage for a few weeks vacation with my wife
>>>> would be can I hot wire the sucker to the other coil HT post and get
>>>> away with it? LOL!
>>>
>>>
>>>
>>> Then you really WILL blow your muffler off.
>>> --scott
>>>
>>
>> well... not if it is a waste spark ignition system and he connects the
>> wire to the other cylinder in that pair.
>>
>> Keep in mind that this is assuming a whole lot of stuff about this
>> particular car that I don't know for sure.
>>
>> nate
>>
> It is a 3300 Olds engine with 3 coil packs for 6 cylinders. The HT
> wires are on one side of each coil pack.
>
> I guess I need two timing lights to see if both fire at once on one of
> the good coil packs.
>
> Mike

Or if you have a timing light with a tach feature, see if the RPM reads
2x as high on the timing light as it does on the dash.

nate

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