1997 Chevy Silverado

"sdlomi2" > wrote in message
...

> Please continue offering your expertise, C-Fish, as many of us benefit
> from and appreciate your ideas. s

I agree, SD. Comboverfish is a professional and a highly knowledgeable
contributor to this site,
as are several others, and I would hate to see them get fed up with this
sort of response.

> wrote:
> "sdlomi2" > wrote in message
> ...
>
> > Please continue offering your expertise, C-Fish, as many of us benefit
> > from and appreciate your ideas. s
>
> I agree, SD. Comboverfish is a professional and a highly knowledgeable
> contributor to this site,
> as are several others, and I would hate to see them get fed up with this
> sort of response.

Thanks, H. Now I'm blushing...


Toyota MDT in MO

sdlomi2 wrote:
> "General" > wrote in message
> ups.com...
> > please stop wasting my time yank.
>
>
> I, for one, do not understand why Comboverfish's comprehensive
> response--obviously laborously created to help one specific person out of
> his plight--called for or deserved such an insulting reply. His responses
> have pretty much all been unselfish sharing of real-world experiences, not
> mere quotes from repair manuals or highly theoretical guesses. He even
> admitted having been 'off the mark' about his analysis of an unusual vehicle
> when he said, "Geez, you ever get the feeling you just wasted 200+
> words?"--obviously a self-deprecating remark and an apparent apology.
> Please continue offering your expertise, C-Fish, as many of us benefit
> from and appreciate your ideas. s

Very kind of you to reply in this manner, Sdlomi2. I appreciate your
contribution to this group as well.

I actually meant that the OP wasted my time by posting incorrect
vehicle info, or not enough info to give a "correct" answer. If he
really had a 1997 Chevy Silverado with 5.7, and I don't care what trim
level, Suburban or truck, short bed, long bed, whatever, then he would
have the Vortec with a distributor -- no coilpacks. His description of
which pairs of cylinders were misfiring was a classic case of cap
crossfiring based on the design of that tried and untrue cap design.
Of course I had to find a picture of one online to verify which
cylinder pairs were most suspect... Neil even replied that the OP must
have a distributor if it is a 97 5.7. He lives up north and knows a
thing or two about Canadian spec vehicles, so I figure his to be a well
considered reply given the OP is somewhere in Canada (apparently). Now
if the OP had a different engine or some aftermarket ignition system
(not likely) it still should have been mentioned.

Enough soapboxing, I just heard the bell ring....
The decision... TKO!
I'll take it...

Toyota MDT in MO

"General" > wrote in news:1169341266.793872.106090
@s34g2000cwa.googlegroups.com:

> I have a 1997 Chevy Silveradoo with a 5.7 litre engine. Recently it has
> started to miss badly when in idle. I had it scoped of which the
> computer stated that at first cylinders 5 and 7 were missing....less
> than a minute later 5 and 7 were firing again but cylinder 4 was now
> missing...then it was neither 5,7, or 4, but only 3 missing. I have
> recently changed all spark plugs and wires less than 60 000km with
> orignal OEM parts (AC Delco). Also, it is becoming harder to start with
> the first turn of the key. I suspect the fuel pump, but was wondering
> if anyone else has had similar symptoms before. Thanks for your input
> into the matter.
>

97 /5.7 L/coil over plug?......not here in the land of plenty. now up there
in the frozen tundra they may have built some *******ized 97 but down here
it wasnt until late 99 when they switched to the 5.3 design......since you
do have coil over plug ign. you should know...*coils fail intermittently*.
yep. all the time.......i see it more in ford than gm but ive replaced many
of single fire coils in the new trucks also. if you truley suspect the fuel
pump a simple guage will tell you if pressure is not adequate when symptoms
appear. if you decide to replace pump make sure you get one made in USA.
those french pumps only work part of the time and surrender under pressure!

Well....first and foremost

the 1997 5.7 has a cap and rotor. Why the heck did I mention coil
packs...I don't know. My response of "don't waste my time yank...was
uncalled for...but my only excuse is that I have been stressed out over
this and have a number of idiots up here in Thundra land telling me the
bloddy thing runs on coil packs....IT DOESN'T ....it runs on cap and
rotor as mention by yourself and AARCUDA in both replies. Your
statement of going to **** myself over this simple problem...well your
right on 50%...I am ****ing myself...but it is not a simple problem. At
least not to this stupid Canadian - the stupid Canadain being myself
and not the idiots that swore to me it is a coil pack.

I did change the cap and rotor... to no avail. Missing still bad while
in idle. next I will change the plugs once again....but I dont beleive
it is the problem either. I should have it scanned again after I change
the plugs.....I have no idea anymore...engine has 300 000 km....thats
about 200 000 plus miles. I'm hoping that it might be an emmisson
sensor problem.....but at this point ....it is really becoming a boat
anchor.

Once again...my apoligies as I continue to **** myself over this
problem...you were right about it runnig on a cap and rotor.....but
unfortunatly...that is not the root cause of this simple problem.



Comboverfish wrote:
> General top posted:
> > please stop wasting my time yank.
>
> I will in no way impede you from ****ing yourself. Good luck with the
> simple problem you can't figure out.
>
> Toyota MDT in MO
>
> > Comboverfish wrote:
> > > aarcuda69062 wrote:
> > > > In article
> > > > om>,
> > > > "General" > wrote:
> > > > >
> > > > > Comboverfish wrote:
> > > > > > General wrote:
> > > > > > > I have a 1997 Chevy Silveradoo with a 5.7 litre engine. Recently it has
> > > > > > > started to miss badly when in idle. I had it scoped of which the
> > > > > > > computer stated that at first cylinders 5 and 7 were missing....less
> > > > > > > than a minute later 5 and 7 were firing again but cylinder 4 was now
> > > > > > > missing...then it was neither 5,7, or 4, but only 3 missing. I have
> > > > > > > recently changed all spark plugs and wires less than 60 000km with
> > > > > > > orignal OEM parts (AC Delco). Also, it is becoming harder to start with
> > > > > > > the first turn of the key. I suspect the fuel pump, but was wondering
> > > > > > > if anyone else has had similar symptoms before. Thanks for your input
> > > > > > > into the matter.
> > > > > >
> > > > > > It's good to hear that you used OE tuneup parts. I'm going to suggest
> > > > > > two mo AC Delco cap and rotor. Your engine has a funky distributor
> > > > > > cap that I can only assume was designed using the 'style over
> > > > > > substance' method. You will notice that the plug wires exit the cap
> > > > > > neatly to the left and right sides, unlike on conventional caps where
> > > > > > each wire is equally spaced around the diameter of the cap. Cool, huh?
> > > > > > The problem is that to make the cap look like that, most of the cap's
> > > > > > spark plug wire terminals aren't anywhere near where the rotor "fires"
> > > > > > their respective cylinders. If you inspect the top of the cap you will
> > > > > > see the molded-in routing that dictates which terminal is fed by which
> > > > > > clock position on the distributor.
> > > > > >
> > > > > > The real damning evidence here is that cylinder 5's plug wire enters
> > > > > > right where the cylinder 7 terminal is inside the cap. It's the same
> > > > > > for the cylinder 4 wire and cylinder 3 terminal. Now you can see why
> > > > > > an ignition crossfire is so likely, and it is also likely that
> > > > > > something like this would be intermittant, setting the misfire codes in
> > > > > > no particular order. The 4/3 combination is *really* close on the cap,
> > > > > > as is the 7/2. There are many problem areas where ignition crossfire
> > > > > > is facilitated on this cap, so you could conceivably see more misfire
> > > > > > codes in the future.
> > > > > >
> > > > > > Try the cap and rotor for ~$50US and see if that takes care of it.
> > > > > >
> > > > > > Toyota MDT in MO
> > > > >
> > > > > Thanks, but there is no Cap....it is individual coil packs for each
> > > > > cylinder. I'm quite certain now it is the fuel pump.
> > > >
> > > > Then it is not a 1997 Silverado with a 5.7.
> > >
> > > Geez, you ever get the feeling you just wasted 200+ words?
> > >
> > > Is a 5.7 litre different in Canada than a US 5.7 liter? Hmmm...
> > >
> > > Toyota MDT in MO

General > wrote:
>
>I did change the cap and rotor... to no avail. Missing still bad while
>in idle. next I will change the plugs once again....but I dont beleive
>it is the problem either. I should have it scanned again after I change
>the plugs.....I have no idea anymore...engine has 300 000 km....thats
>about 200 000 plus miles. I'm hoping that it might be an emmisson
>sensor problem.....but at this point ....it is really becoming a boat
>anchor.

So what does a timing light tell you?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

General wrote:
> Well....first and foremost
>
> the 1997 5.7 has a cap and rotor. Why the heck did I mention coil
> packs...I don't know. My response of "don't waste my time yank...was
> uncalled for...but my only excuse is that I have been stressed out over
> this and have a number of idiots up here in Thundra land telling me the
> bloddy thing runs on coil packs....IT DOESN'T ....it runs on cap and
> rotor as mention by yourself and AARCUDA in both replies. Your
> statement of going to **** myself over this simple problem...well your
> right on 50%...I am ****ing myself...but it is not a simple problem. At
> least not to this stupid Canadian - the stupid Canadain being myself
> and not the idiots that swore to me it is a coil pack.
>
> I did change the cap and rotor... to no avail. Missing still bad while
> in idle. next I will change the plugs once again....but I dont beleive
> it is the problem either. I should have it scanned again after I change
> the plugs.....I have no idea anymore...engine has 300 000 km....thats
> about 200 000 plus miles. I'm hoping that it might be an emmisson
> sensor problem.....but at this point ....it is really becoming a boat
> anchor.
>
> Once again...my apoligies as I continue to **** myself over this
> problem...you were right about it runnig on a cap and rotor.....but
> unfortunatly...that is not the root cause of this simple problem.

Stuck CPI injector poppets (nozzles) are a common problem after a hot
soak on the Vortec. Some people try injector cleaner, but it's
unlikely to work if the poppets are currently stuck closed. Some have
had success with (regulated) compressed nitrogen in the fuel rail, then
operating the 8 fuel solenoids with a Tech2. I have not done this but
it sounds like the easiest, best method given that you have the
equipment.

Toyota MDT in MO

General wrote:
> Well....first and foremost
>
> the 1997 5.7 has a cap and rotor. Why the heck did I mention coil
> packs...I don't know. My response of "don't waste my time yank...was
> uncalled for...but my only excuse is that I have been stressed out over
> this and have a number of idiots up here in Thundra land telling me the
> bloddy thing runs on coil packs....IT DOESN'T ....it runs on cap and
> rotor as mention by yourself and AARCUDA in both replies. Your
> statement of going to **** myself over this simple problem...well your
> right on 50%...I am ****ing myself...but it is not a simple problem. At
> least not to this stupid Canadian - the stupid Canadain being myself
> and not the idiots that swore to me it is a coil pack.
>
> I did change the cap and rotor... to no avail. Missing still bad while
> in idle. next I will change the plugs once again....but I dont beleive
> it is the problem either. I should have it scanned again after I change
> the plugs.....I have no idea anymore...engine has 300 000 km....thats
> about 200 000 plus miles. I'm hoping that it might be an emmisson
> sensor problem.....but at this point ....it is really becoming a boat
> anchor.
>
> Once again...my apoligies as I continue to **** myself over this
> problem...you were right about it runnig on a cap and rotor.....but
> unfortunatly...that is not the root cause of this simple problem.

I should also mention that you should check fuel pressure. Typical
fuel pressure is between 54 and 60 psi on that engine. Anything less
than low 50's will not open the poppets reliably, and cause a no start
or poor run condition.

Toyota MDT in MO

In article
. com>,
"Comboverfish" > wrote:
>
> Stuck CPI injector poppets (nozzles) are a common problem after a hot
> soak on the Vortec. Some people try injector cleaner, but it's
> unlikely to work if the poppets are currently stuck closed. Some have
> had success with (regulated) compressed nitrogen in the fuel rail, then
> operating the 8 fuel solenoids with a Tech2. I have not done this but
> it sounds like the easiest, best method given that you have the
> equipment.
>
> Toyota MDT in MO

Good call on the stuck poppets.
Shame on me, I've been using compressed air.
100% success rate though...
(just ask my brother in law who's too cheap to use a bottle of
Techron a couple of times a year.)

Is it possible that you run by me the routine for compressed stuck
injectors? I should also mention that it has been an extremly cold week
here....temperature dropped below -40C which is the same as -40F. Truck
was left outside plugged in (oil/block heater) on overnight. It seemed
that after the first night of this unbearable cold...it started it's
miss in idle. I'm thinking that perhaps this extrem cold weather might
have froze the injectors shut. I dont have nitrogen avaiable...but
compressed air might do the trick.

Sincerly...****ed and stuck on the missing problem.