94 surging/bucking problem

charlie wrote:

> 100k miles ago, at least.
>
>
You ARE joking, aren't you????

charlie wrote:

>>> i have a problem with my 94 that is puzzling me.
>
> 100k miles ago, at least.

I've never replaced the plugs in my '93. I'm still running the ones from
the factory. It still runs great. I've only got 62K miles on it though.

I had a similar symptom on my '85. The pro's diagnosed bad fuel filter,
then bad fuel pump. When the after market fuel pump that they put in it
failed, I took it to the Chevy dealer. The Chevy dealer told me it was
the injectors, and charged me a fortune. It finally turned out to be the
MAF.

Hope this helps.

"WayneC" > wrote in message
...
> charlie wrote:
>
>> 100k miles ago, at least.
>>
>>
> You ARE joking, aren't you????

nope. it still gets 24mpg in town, 30mpg on long distance trips. this is my
daily driver as well as my long distance traveler. i put on 300+ miles/week
commuting, and multi-thousand mile trips. it's been rock solid for over 10
years. why fix something that hasn't been a problem?

i don't think bad plugs/wires will cause surging, uncalled for speedups,
idle seeking, and higher or lower than normal idling. it might account for
the missing, but unless 2 problems happened at the same time, there's
something else going on. i asked over at the corvette action center, and
someone suggested an egr, which also has never been replaced since i got the
car. that, i believe, can cause this problem, and seems to have the same
symptoms that others have seen elsewhere.

regards,
charlie
cave creek, az

"JimH" > wrote in message
...
> charlie wrote:
>
> >>> i have a problem with my 94 that is puzzling me.
> >
> > 100k miles ago, at least.
>
> I've never replaced the plugs in my '93. I'm still running the ones from
> the factory. It still runs great. I've only got 62K miles on it though.
>
> I had a similar symptom on my '85. The pro's diagnosed bad fuel filter,
> then bad fuel pump. When the after market fuel pump that they put in it
> failed, I took it to the Chevy dealer. The Chevy dealer told me it was the
> injectors, and charged me a fortune. It finally turned out to be the MAF.
>
> Hope this helps.

thanks. hope not. wouldn't a maf failure throw a code?

i actually had almost exactly this same symptoms on my 89. many hundreds of
dollars later after the pros replaced the egr, injectors, maf, maf relays,
it turned out to be the iac. that's why i tried that first, and
unfortunately, it wasn't the same problem.

regards,
charlie
cave creek, az

charlie wrote:
> "Bob I" > wrote in message
> ...
>> When was the last time the spark plugs were checked/changed?
>>
>> charlie wrote:
>>> hello
>>>
>>> i have a problem with my 94 that is puzzling me.
>>>
>>> 6speed
>>> 140k miles
>>> no ses light
>>> service ride control (z07 option) light is on, but that is a bad servo
>>> that i know about
>>> no other indicators on
>>> new battery
>>> alternator normal output
>>> all other temp indicators in normal ranges
>>>
>>> the symptoms started a few months ago. in top gear at high way speeds, it
>>> will seem to miss when a demand is placed on the engine (going up a hill,
>>> passing, etc). in the ensuing months, it seems to have gotten worse, in
>>> that it now:
>>>
>>> at idle (which used to be around 800rpm), it would start to hunt, going
>>> from 800-2000, with no throttle input. during around town driving, say in
>>> 4th at 45, the engine would speed up so the car would accelerate, with no
>>> throttle changes being done by me. the pedal doesn't move under my foot,
>>> so it's not a spring, i believe.
>>>
>>> i replaced the iac valve and airfilter at this point. when the old one
>>> iac was removed, it had a lot of crud on it. i cleaned out the opening to
>>> the throttlebody, but didn't take it off for a complete cleaning. i also
>>> replaced the water temp sensor, as i noticed the harness connector was
>>> cracked.
>>>
>>> the problem has now changed, in that the idle has dropped to an abnormal
>>> low of 400 and seems to almost stall. it still has the missing and
>>> bucking at constant speeds, and also misses pulling away from a stop.
>>>
>>> i took it to my local mechanic, whom i've had for about 20 years. he
>>> noticed that every time it surges, the service ride control light changes
>>> intensity. he seems to feel that the computer is bad and is affecting the
>>> timing somehow, and said i should take it to the chevy dealer.
>>>
>>> could this be a fuel delivery problem (fuel pump, filter, bad injectors)?
>>>
>>> are there any other sensors that this could be, or does this sound
>>> familiar, and if so, are there tests for them so i don't have to start
>>> throwing expensive parts at the problem?
>>>
>>> thanks,
>>> charlie
>>> cave creek, az
>
> 100k miles ago, at least.
>
>

I'd check them cause it's one of the things that won't throw a code, and
it fits both symptoms in my 95 manual.

All the guys that go 50,000+ on the original spark plugs are all
losers. This is a losing thread.

=========================================
On Wed, 02 May 2007 12:10:27 -0700, WayneC >
wrote:

>charlie wrote:
>
>> 100k miles ago, at least.
>>
>>
>You ARE joking, aren't you????

I have an '84 crossfire and have a very similair problem.. When at low spped
with no extreme power requirements the engine 'surges', I have replaced
virtually everything (including the power brake vacuum booster) thinking it
must be a vacuum issue. I am down to the point that it is probably the
injectors but on the crossfire they are about $600.00 each. I'm saving my
money for the two injector replacements now.

I hope this works or I think it will force me to result to carburation.


"Bob I" > wrote in message
...
>
>
> charlie wrote:
> > "Bob I" > wrote in message
> > ...
> >> When was the last time the spark plugs were checked/changed?
> >>
> >> charlie wrote:
> >>> hello
> >>>
> >>> i have a problem with my 94 that is puzzling me.
> >>>
> >>> 6speed
> >>> 140k miles
> >>> no ses light
> >>> service ride control (z07 option) light is on, but that is a bad servo
> >>> that i know about
> >>> no other indicators on
> >>> new battery
> >>> alternator normal output
> >>> all other temp indicators in normal ranges
> >>>
> >>> the symptoms started a few months ago. in top gear at high way speeds,
it
> >>> will seem to miss when a demand is placed on the engine (going up a
hill,
> >>> passing, etc). in the ensuing months, it seems to have gotten worse,
in
> >>> that it now:
> >>>
> >>> at idle (which used to be around 800rpm), it would start to hunt,
going
> >>> from 800-2000, with no throttle input. during around town driving, say
in
> >>> 4th at 45, the engine would speed up so the car would accelerate, with
no
> >>> throttle changes being done by me. the pedal doesn't move under my
foot,
> >>> so it's not a spring, i believe.
> >>>
> >>> i replaced the iac valve and airfilter at this point. when the old one
> >>> iac was removed, it had a lot of crud on it. i cleaned out the opening
to
> >>> the throttlebody, but didn't take it off for a complete cleaning. i
also
> >>> replaced the water temp sensor, as i noticed the harness connector was
> >>> cracked.
> >>>
> >>> the problem has now changed, in that the idle has dropped to an
abnormal
> >>> low of 400 and seems to almost stall. it still has the missing and
> >>> bucking at constant speeds, and also misses pulling away from a stop.
> >>>
> >>> i took it to my local mechanic, whom i've had for about 20 years. he
> >>> noticed that every time it surges, the service ride control light
changes
> >>> intensity. he seems to feel that the computer is bad and is affecting
the
> >>> timing somehow, and said i should take it to the chevy dealer.
> >>>
> >>> could this be a fuel delivery problem (fuel pump, filter, bad
injectors)?
> >>>
> >>> are there any other sensors that this could be, or does this sound
> >>> familiar, and if so, are there tests for them so i don't have to start
> >>> throwing expensive parts at the problem?
> >>>
> >>> thanks,
> >>> charlie
> >>> cave creek, az
> >
> > 100k miles ago, at least.
> >
> >
>
> I'd check them cause it's one of the things that won't throw a code, and
> it fits both symptoms in my 95 manual.
>

"Art" > wrote in message
...
>I have an '84 crossfire and have a very similair problem..
>When at low spped
> with no extreme power requirements the engine 'surges', I
> have replaced
> virtually everything (including the power brake vacuum
> booster) thinking it
> must be a vacuum issue. I am down to the point that it is
> probably the
> injectors but on the crossfire they are about $600.00
> each. I'm saving my
> money for the two injector replacements now.
>
> I hope this works or I think it will force me to result to
> carburation.

my 84 done the same thing.
don't be to quick to replace injectors.
Is your fuel tank clean of debris?
have you checked for proper fuel pressure?
did you check/replace fuel pump, and fuel filter?
have you run injector cleaner ? (recommend Lucus Fuel
injector cleaner)

--
"Key"
=====

I have not replace the fuel pump but have checked it at most rpms and it is
steady, I have run several injector cleaners, replaced the fuel filter and
tps, new cam, rollers, solids, but had issue prior to new cam and solids, I
have even replaced the brake vacuum booster thinkingit may be a vacuum
issue.

I am down to the injectors or I dant know what accept maybe the ECM?

Art
"'Key" > wrote in message
. ..
> "Art" > wrote in message
> ...
> >I have an '84 crossfire and have a very similair problem..
> >When at low spped
> > with no extreme power requirements the engine 'surges', I
> > have replaced
> > virtually everything (including the power brake vacuum
> > booster) thinking it
> > must be a vacuum issue. I am down to the point that it is
> > probably the
> > injectors but on the crossfire they are about $600.00
> > each. I'm saving my
> > money for the two injector replacements now.
> >
> > I hope this works or I think it will force me to result to
> > carburation.
>
> my 84 done the same thing.
> don't be to quick to replace injectors.
> Is your fuel tank clean of debris?
> have you checked for proper fuel pressure?
> did you check/replace fuel pump, and fuel filter?
> have you run injector cleaner ? (recommend Lucus Fuel
> injector cleaner)
>
> --
> "Key"
> =====
>
>
>

"Art" > wrote in message
.. .
>I have not replace the fuel pump but have checked it at
>most rpms and it is
> steady, I have run several injector cleaners, replaced the
> fuel filter and
> tps, new cam, rollers, solids, but had issue prior to new
> cam and solids, I
> have even replaced the brake vacuum booster thinkingit may
> be a vacuum
> issue.
>
> I am down to the injectors or I dant know what accept
> maybe the ECM?
>
> Art

well, I am out of suggestions.
maybe someone else here will be of help?
when you find out the source of the problem.
please return and post it. I am courious to know.

g'luck
--
"Key"
=====

> "'Key" > wrote in message
> . ..
>> "Art" > wrote in message
>> ...
>> >I have an '84 crossfire and have a very similair
>> >problem..
>> >When at low spped
>> > with no extreme power requirements the engine 'surges',
>> > I
>> > have replaced
>> > virtually everything (including the power brake vacuum
>> > booster) thinking it
>> > must be a vacuum issue. I am down to the point that it
>> > is
>> > probably the
>> > injectors but on the crossfire they are about $600.00
>> > each. I'm saving my
>> > money for the two injector replacements now.
>> >
>> > I hope this works or I think it will force me to result
>> > to
>> > carburation.
>>
>> my 84 done the same thing.
>> don't be to quick to replace injectors.
>> Is your fuel tank clean of debris?
>> have you checked for proper fuel pressure?
>> did you check/replace fuel pump, and fuel filter?
>> have you run injector cleaner ? (recommend Lucus Fuel
>> injector cleaner)
>>
>> --
>> "Key"
>> =====
>>
>>
>>
>
>