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Discussion Starter #1
I had a bad Spark wire and replaced all of those and installed a new ICM and Coil. Car seems to run well with the Throttle wide open and shifts fine.

The Problem - When just driving normally and the car goes thru all shifts fine. However, if just cruising at normal throttle and start to go up a hill or sometimes as the car shifts under light throttle, I will get what I best descibe as the engine shaking and almost seems under power. As this happens, if I give it more gas the shaking seems to stop and the engine runs fine. It only does this under light throttle/load scenarios.

So after checking all I could and not finding anything obvious, I took it to my mechanic that does my state inspections to see if he could diagnose the problem. Thought another set of eyes would be a help and I was still leaning toward an ignition issue. He was nice enough to check it all out and found really nothing wrong with the engine or engine sensors. His best Guess was a "problem with the Lockup in the Torque Converter. I know there are solenoids in the trans and think they help control this. He recommended I talk to a Trans shop and see what they find.

So what do you guys think? Is this a possibility and could it just be something simple in the trans, maybe a bad TC or anynuber of other things I should look at?? A little background....The car was running great about 8 months ago and then the ICM died and I let it sit for 8 months before working on it. Fixed the ICM/Coil issue and then this showed up as the problem. Any ideas/thoughts are welcome....Thx.
 

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Had one of these with a leaky EGR valve that was letting too much EGR in at light loads which caused a slight shaking/low power condition. More throttle reduces EGR request by the PCM as well as masks the EGR with more fresh air.

Unplug the vacuum line to the EGR actuator (and plug the line) and see if it goes away?
 

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OP

if what you describe is a "misfire" under load...that often is a plug/wire arc. I believe you have chased that "what if" in your other post

Your mechanic could be on this with the TC note.....but it could still be some corrupted wire/connection within the ignition system....which needless to say is insanely tedious to check through the several feet of wiring & connectors.

At this point maybe a tranny shop who can scan for tranny codes and do a pressure test can determine if it is a TC or "internal" trans issue is prudent as your "symptoms" can be that

Maybe someone more Auto Trans can jump in to coment

I am going to WAG a hail marry here but have you checked U joints, nothing "grounding" (exhaust) on x member/frame??

and circling back to plug wires, you using any stock plug boot heat shields?...and if so you sure there is no arc between boot and inside shield (read you won't see this but you can hear it unless you are really in dark condition)
 

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Discussion Starter #4
Had one of these with a leaky EGR valve that was letting too much EGR in at light loads which caused a slight shaking/low power condition. More throttle reduces EGR request by the PCM as well as masks the EGR with more fresh air.

Unplug the vacuum line to the EGR actuator (and plug the line) and see if it goes away?
Very interesting as this did cross my mind already and the F-Body/Manual Trans EGR is looooong overdue for replacement anyway. I'll be sure to test this out this weekend and will order a new F-Body EGR.

OP

if what you describe is a "misfire" under load...that often is a plug/wire arc. I believe you have chased that "what if" in your other post

Your mechanic could be on this with the TC note.....but it could still be some corrupted wire/connection within the ignition system....which needless to say is insanely tedious to check through the several feet of wiring & connectors.

At this point maybe a tranny shop who can scan for tranny codes and do a pressure test can determine if it is a TC or "internal" trans issue is prudent as your "symptoms" can be that

Maybe someone more Auto Trans can jump in to coment

I am going to WAG a hail marry here but have you checked U joints, nothing "grounding" (exhaust) on x member/frame??

and circling back to plug wires, you using any stock plug boot heat shields?...and if so you sure there is no arc between boot and inside shield (read you won't see this but you can hear it unless you are really in dark condition)
Yeah, think a Trans Shop consult is in my future. But still going to try some other things like the EGR mentioned above and I know the IAC is very old also and noticed surging while in gear and at idle and just think it's time for a new 1 there as well.

U-joints and all are good and run a Dynotech D/S. When installing the new Taylor wires, I just used those Cloth Socks? over the Plug boots and used Dielectric Grease on both sides of the wires. I really hope it's not something in the trans (expensive) but if it is, it will finally be the excuse I need to up the Stall and go with a performance converter.
 

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Discussion Starter #5
Just ordered a AC Delco #214-5083 from RockAuto. This part was about $67 on their site and Autozone had it listed at $151 !!! This is the EGR used in a 95 Camaro with 5.7 and Manual Trans. I haven't done any testing yet of the old EGR and knew I want to replace this anyway. Will report back after I disconnect the line, plug it and take for a test drive. I also did the EGR solenoid when I last replaced this and will probably replace that as well and think they only run about $20 and will just get at the local parts store.
 

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I had a similar shudder under light loads. I put some anti-shudder (sp) from NAPA in the trans, and it stopped. I also had the trans go out a couple of months later. If the anti-shudder (sp) works, get ready to replace the trans.
 

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Discussion Starter #7
I had a similar shudder under light loads. I put some anti-shudder (sp) from NAPA in the trans, and it stopped. I also had the trans go out a couple of months later. If the anti-shudder (sp) works, get ready to replace the trans.
Well damn Fred, I was having an otherwise good morning.....Mr. Davey Downer :smile2:

JK, I understand and prepared for the worst if that happens. Nothing to lose with dumping a bottle in there after I see what (if needed) a trans shop says. I am a hard driver on that trans but just the otherday when getting on it, that thing still chirped as it grabbed 2nd and still seems to shift fine/firm. So I'm hopeful it's not something internal of the trans and more of a sensor and even considering throwing my spare (Stock Tune) ECM on there just to see what that does. I hate these types of problems when there can be so many possibilities.
 

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Well damn Fred, I was having an otherwise good morning.....Mr. Davey Downer :smile2:

JK, I understand and prepared for the worst if that happens. Nothing to lose with dumping a bottle in there after I see what (if needed) a trans shop says. I am a hard driver on that trans but just the otherday when getting on it, that thing still chirped as it grabbed 2nd and still seems to shift fine/firm. So I'm hopeful it's not something internal of the trans and more of a sensor and even considering throwing my spare (Stock Tune) ECM on there just to see what that does. I hate these types of problems when there can be so many possibilities.
I would NOT recommend putting something like that in a transmission that's otherwise functioning fine. The "stuff" in those cans actively attacks the seals and makes them swell so they seal again, however it also weakens them as well so they will fail.

Think of the seals like pasta - Normally (as you would eat it) it's soft but strong and flexible. The seals do their job well.
If the trans is overheated or has lots of wear, the seals get hard and brittle - Like pasta before it's cooked - hard and brittle so they leak until there's enough flow across them to saturate the leak or push the seal out and fill the gap. This causes late/hard shifts when the seal suddenly engages, slow/sloppy transitions or binds as the seals randomly do their job.
When you put a quart of magic fluid in the transmission, it's like soaking your pasta in water overnight. It swells up and is flexible again, but has no strength - the pasta (seals) turn to sloppy mush. It may improve things for a while, but soon that mush dissolves, the seal fails and you're walking.

If you're otherwise going to rebuild the trans, there's other signs of problems there (stuff in the pan, long delays/shifts when cold/hot, "wierd" operation, etc) then not much to loose and it can buy you a few thousand miles, but on a trans without any other signs of trouble, my opinion/experience is that you will have more trouble than if you had just left it alone.
 

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First I would suggest some live data. Do a test drive and have someone else call out when the transmission goes in and out of lockup. Do the same for the EGR % .
TC state was important enough on some of the old scanners that it was always displayed by a separate display light.


I do not like chemical additives but I use some from time to time. I have used Lubegard 19610 Dr. Tranny Instant Shudder Fixx . It does not promise to do all things. It is not a seal swelling product. All it claims is that it has friction chemicals that may not be at the correct leveled in your transmission fluid(new/old).


The early ford 4R70W had shudder problems and the recalls to program the PCM did not always fix it. Many ford owners swear the Dr worked. It has a good reputation as far as I have looked.
 

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Hi, if you want another guess, rule out the fuel injector connectors.
Maybe test light check to verify all 8 are firing ?

my car ran on 7 and i could hardly tell. i think the shielding in #7 was okay but the wire inside was broken.

I agree with Canada, get some data to luckily rule stuff out if possible.

-ALF out...
 

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..... However, if just cruising at normal throttle and start to go up a hill or sometimes as the car shifts under light throttle, I will get what I best descibe as the engine shaking and almost seems under power. As this happens, if I give it more gas the shaking seems to stop and the engine runs fine. It only does this under light throttle/load scenarios.

.

You 100% describe what I would experience with cruise control at exactly the same spot on the hiway starting up a long incline heading to a weekend at the lake. It was exactly the same common vibrating "chuggle" I remembered years back on other cars with a sluggish TC solenoid trying to get out of lockup. Even if it had been a month between this 3-hour drive I still automatically remembered at the start just to add a little pedal myself and keep it locked up and smooth.

Cliffs: I think your mech. is on the right track. And then there's the common 'Where's Waldos', plus all the other stuff mentioned;






 

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Discussion Starter #12
First I would suggest some live data. Do a test drive and have someone else call out when the transmission goes in and out of lockup. Do the same for the EGR % .
TC state was important enough on some of the old scanners that it was always displayed by a separate display light.
Thats a good call...I really need to take the time to get my Laptop "Familiar" with my car and I NEED to learn how to use my lappy to scan this stuff. I have a ODB1 cable, do you have a program you would recommend that could diagnose these things?
 

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Discussion Starter #13
Hi, if you want another guess, rule out the fuel injector connectors.
Maybe test light check to verify all 8 are firing ?

my car ran on 7 and i could hardly tell. i think the shielding in #7 was okay but the wire inside was broken.

I agree with Canada, get some data to luckily rule stuff out if possible.

-ALF out...
I did pull all 8 injector wires and tested each plug with a Noid Light and they all worked. I just replaced all the injectors and they maybe have a few thousand miles on them. They all "ohmed" out right when I checked each of them.

You 100% describe what I would experience with cruise control at exactly the same spot on the hiway starting up a long incline heading to a weekend at the lake. It was exactly the same common vibrating "chuggle" I remembered years back on other cars with a sluggish TC solenoid trying to get out of lockup. Even if it had been a month between this 3-hour drive I still automatically remembered at the start just to add a little pedal myself and keep it locked up and smooth.

Cliffs: I think your mech. is on the right track. And then there's the common 'Where's Waldos', plus all the other stuff mentioned;






Yeah,I need to go over some things. In that 3rd Pic is that the MAP Sensor and guess you are showing the Gasket for that? I would say mine is original and not sure if this would cause that. I kinda remember a Harley Davidson part that could replace this orange gasket.

Ahhh, you mentioned "Chuggle" and I think there is one of those Buick Know How videosout there that talks about this issue. I'll see if I can find it.

Thx again everyone for ideas. I hate to just throw parts at the car but with the age of some of these sensors, maybe I should just replace them anyway with new GM.
 

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QUOTE:.......... "In that 3rd Pic is that the MAP Sensor and guess you are showing the Gasket for that? I would say mine is original and not sure if this would cause that. I kinda remember a Harley Davidson part that could replace this orange gasket. ".......

I bought a box of 10 with the HD # for a fraction of the price using the car part no., and that pic is from my old '95 FWB at 170,XXX, and I did my black '96 plus the '96 FWB I bought 3 years ago. They all looked pretty gnarly - jammed on crooked and flattened to nothing. I chased irksome gremlins for a couple months after buying the FWB along with attending all the normal maint. items. Doing a new PCV I discovered the hidden hole in the elbow. Even with only 52,XXX the vacuum leaks were still pretty sneaky considering all the 20+ year old rubber parts and pieces.

Now, with 75,XXX the car is running perfect and there's no indication of intake leak(s), but it's starting to bother me that I haven't done new intake gaskets and RTV yet anyway - just because.... lol

Oh and BTW and FTR, it's only considered foolishly 'throwing parts at it' as a reactive measure to repairing breakdowns with no diagnosis first. It's proactive programmed periodic maint. if replacing those exact the same parts because they're just plain worn out 2-decades old regular production car parts, - thus averting most gremlins and especially chopping them off at the knees from progressing into breakdowns.

Me with maint. items: I'm gonna kill them all, sir."




:: preaches off:: ;)
 

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4DoorSS

IIRC there is a free download for OBD 1 cars called Scan9495 for OBD1. IDK if it shows transmission stuff but may.

+2 on the HD MAP orange grommet. Can't remember what year(s) Harley but it is a direct fit for about $4. I just went into my local Harley dealer and they searched a few years to find the right one in their parts list

Like the various hoses that are rotted shown any of those can be cumulative/contributing factors for making a engine not run tip top

Your "under load" shudder could likely be tranny related if not some hidden plug arc going on.
 

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Discussion Starter #17 (Edited)
Had one of these with a leaky EGR valve that was letting too much EGR in at light loads which caused a slight shaking/low power condition. More throttle reduces EGR request by the PCM as well as masks the EGR with more fresh air.

Unplug the vacuum line to the EGR actuator (and plug the line) and see if it goes away?
THANK YOU!!!!!! Owe you a virtual Yeungling my friend.

Had the same exact issue...Bad EGRRRRRR! The old one would not hold vacuum. Installed a new AC Delco #214-5083 (95 Camaro with Manual trans) took it for a little drive...ALL GOOD. When it drops into Overdrive, it just drives nice and smooth. :smile2::smile2: Wanted to take it on a much longer drive but it's dark and we got critters all over the place. :frown2:
 

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Gladja foundit. Some real enterprising (but bored to tears) soul should get a spreadsheet and list & sort ALL the things in the off-idle stumble stickie in order of most frequent culprits. ;)
 

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THANK YOU!!!!!! Owe you a virtual Yeungling my friend.

Had the same exact issue...Bad EGRRRRRR! The old one would not hold vacuum. Installed a new AC Delco #214-5083 (95 Camaro with Manual trans) took it for a little drive...ALL GOOD. When it drops into Overdrive, it just drives nice and smooth. :smile2::smile2: Wanted to take it on a much longer drive but it's dark and we got critters all over the place. :frown2:
No problem - glad you figured it out!

Go ahead and have a Yeungling in my name - You deserve it more than I do :).
 

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Gladja foundit. Some real enterprising (but bored to tears) soul should get a spreadsheet and list & sort ALL the things in the off-idle stumble stickie in order of most frequent culprits.
It would be nice to know the probability of part failure. Then one could test the probable parts in a more logical order.


I took it to my mechanic that does my state inspections to see if he could diagnose the problem. Thought another set of eyes would be a help and I was still leaning toward an ignition issue. He was nice enough to check it all out and found really nothing wrong with the engine or engine sensors. His best Guess was a "problem with the Lockup in the Torque Converter.
If he had done a live data scan road test and noticed that the "shudder occurs after TCC" The FSM is very specific that it is not a TC or transmission problem and lists 17 choices. Plug wires, coil, ICM, OPTI, fuel injector, vacuum leak, and EGR top this list.
 
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