sort of stumble at idle

[gmjunkie]

Maybe you need to run down Bat Cave Rd so the Vette will run like a bat out of heck! otfl

I will be on the road for a little while, so you can always update me via the old technology of a telephone!

I HOPE YOU BEEN TRYING TO SAVE THE

I believe that is Bat Cave Rd!!Anyway,I think the last little problem was heat soak!!Got up early this morning and she fired right up and ran Great!! Took it out and ran the dog weenies out of it and it ran super till I shut it off for about 10 minutes,started it back up and it started Blowing black smoke and then cleared back up!!Thought about it awhile while checking connections and noticed that the Heat sink on the back of the ignition module was really hot!! So I made me a Insulator between the head and module heat sink and it's ran great and not done it since!!

I've not babied it at all today either!!

If it's gonna freak out again,I want it to freak on me and not a customer!!

 

[John Robinson]

OK Junk the picture is great but I need a little more info about what you did and how so I can see if I have the same problem with mine running great cold and then going bad when it gets hot. Since mine as I said does not break down until the temp is about 200 F I also am wondering if the ECM or something else is going into another mode at that temp that is my problem?

Toms94 do you have an update on yours yet from your mechanic????

 

[G Winter]

I know nothing about the Lt setups. Where is this module located ? You seem to have it isolated to heat soak but why now and never before ? Something change? I would be worried about what causes the heat issue.
Would the bad ground have caused the module to get high amperage and damage it to make it more sensitive to heat,which in turn means it is planning on failing ?
This all just seems to be a strange turn of events.


Glenn

 

[formul8]

I took the ICM off mine last week and cleaned the gunk off the heat sink and put dialectric grease on the back of the module and the heat sink. Used to miss when the engine got warm and it does not do that anymore.

Also, I did the intake manifold gaskets over the weekend and found a big spot of gunk on the #5 injector that was blocking two or three of the spray holes. Cleaned the gunk off and the car runs great and no more stumble or miss!

 

[Toms007]

OK Junk the picture is great but I need a little more info about what you did and how so I can see if I have the same problem with mine running great cold and then going bad when it gets hot. Since mine as I said does not break down until the temp is about 200 F I also am wondering if the ECM or something else is going into another mode at that temp that is my problem?

Toms94 do you have an update on yours yet from your mechanic????

John, I am going to check on it tomorrow. He didn't call me today, so I have a Dr. appointment (hopefully the last check, resulting from me shooting myself in the hand with the staple gun 6 weeks ago) and while I am in the "city" I will check on the progress of my car.

 

[gmjunkie]

I know nothing about the Lt setups. Where is this module located ? You seem to have it isolated to heat soak but why now and never before ? Something change? I would be worried about what causes the heat issue.
Would the bad ground have caused the module to get high amperage and damage it to make it more sensitive to heat,which in turn means it is planning on failing ?
This all just seems to be a strange turn of events.


Glenn

I've had a couple different Modules,TPS's,IAC's,ECM's and Mass Air Flow Senors on it in the past 2 weeks trying to Isolate the problems I've been having!! Bad ground at the back of the engine was what I think was causing the Idle and Dieing problem!! The whole problem started about 2 days after I used some new fangled engine 2 in 1 Degrease and Shine by Black Magic that was at advance auto parts on sale 2 for 1!!
The can said............
"No Wrapping Required"
"Cleans,Decreases and Shines in 1 easy step"!!
"Safe for ALL Engine parts"!
"No Pressurized water Required"!!
Just spray on warm engine,allow to stand 15 min and rinse with light flow of water!! Run engine till dry!!

As far as why I think the last 2 times is Heat Soak,I have driven the car 5-6,000 miles since I've had it and never had one problem,But I have NEVER drove it Like I stoled it!! Both times that it has done this the last 2 days,I've been driving it like Mario Andriette and it was performing Perfectly for several miles and I shut it off for 10 -15 minutes!! 1 time it set a code Smoked Black,Popped,Missed and Backfired but started cleared out and got me home, the second time it smoked and missed a little and cleared out and ran good!!
After looking,thinking about it,shooting the Ignition module with my IR gun and finding it about 200+ deg,I decided that the way it's mounted don't make any since!Why lay the heat sink flat against the steel bracket that is mounted flat against the head to absorb that heat too!! So I made a insulator out of 1/6th thick neoprene gasket material that covers the complete back side of the heat sink between the steel bracket,used dielectric grease between the module and heat sink!! I've took it out and flogged heck out of it several times now,it's not had any problems starting after shut down,and the module has never been over 168-175 deg since!! I've never had this problem before,but I think this will become a Standard "GMJunkie" Modification on 92-96 LT1/LT4 engines!!

 

[LT4man]

I believe that is Bat Cave Rd!!

It IS Bat Cave Rd. At least according to Mapquest, it is!!! The internet is a wonderful thing.

Just doing my job. Part of the team. Glad to be here.

Carry on! :L

DID YOU WAVE TO ANY VETTES ON BAT CAVE RD ?

 

[LT4man]

OK Junk the picture is great but I need a little more info about what you did and how so I can see if I have the same problem with mine running great cold and then going bad when it gets hot.

John, because your Vette is a 93 and not new anymore, I can see this being a maintenance problem.

I installed an Accel HP ignition coil a couple of years ago. You have to remove the IM (Ignition Module) when you remove the coil. I made sure to put plenty of dielectric grease on the base of the IM.

I have over 100,000 miles on my LT4 engine and have never experienced any hot soak issues.

You might remove your ignition coil and IM to clean, recoat with grease on the base and reinstall. You might have "stumbled" upon your fix for your "stumble"!

Or make a heat insulator like junkman did and you should be good to go!

SAVE THE

 

[Toms007]

Stopped at the mechanic this morning and he hasn't had a chance to start on it. Another job he was doing turned into a real mess and he was still working on that...so I'll wait a little longer, no big deal to me. I told him to take his time.

 

[John Robinson]

John, because your Vette is a 93 and not new anymore, I can see this being a maintenance problem.

You might remove your ignition coil and IM to clean, recoat with grease on the base and reinstall. You might have "stumbled" upon your fix for your "stumble"!

Or make a heat insulator like junkman did and you should be good to go!

Ok I will do that. As I understand it the ignition coil is on the right side of the engine and is were the hot wire to the Opti goes. I will remove it and get some dielectric to put on it.
I Think you may be right about this may be a maintenance item as the age creeps up on the car. Also I sprayed the heck out of this area with CRC brake cleaner to clean up the grease and antii freeze that was all over the engine. As I understand Junks comments he used a cleaner to clean his engine and his problems started. The common denominater I see here is we both used a solvent that could have removed what ever was used by GM for the heat sink. I hope this is the case since it certainly would be cheaper then a new opti :crazy

 

[gmjunkie]

Ok I will do that. As I understand it the ignition coil is on the right side of the engine and is were the hot wire to the Opti goes. I will remove it and get some dielectric to put on it.
I Think you may be right about this may be a maintenance item as the age creeps up on the car. Also I sprayed the heck out of this area with CRC brake cleaner to clean up the grease and antii freeze that was all over the engine. As I understand Junks comments he used a cleaner to clean his engine and his problems started. The common denominater I see here is we both used a solvent that could have removed what ever was used by GM for the heat sink. I hope this is the case since it certainly would be cheaper then a new opti :crazy

I've always used a mild cleaner of some sort and my steam jenny on my engines!! Usally it's a little Dawn or Lemon Joy though!! This time I seen this stuff that was supposed to be safe for All Engine Parts and Easier than my way and less steps!!I should have just left well enough alone,it wasn't nasty just 2-3,000 miles of road dust!!I wouldn't use brake cleaner though,that would definitely wash Dielectric grease out and swell the rubber seals in the wiring plugs!
PS Mine is still running Perfectly this morning!!

 

[John Robinson]

Guess What

Take a look at this

 

[LT4man]

Ok I will do that. As I understand it the ignition coil is on the right side of the engine and is were the hot wire to the Opti goes. I will remove it and get some dielectric to put on it.
I Think you may be right about this may be a maintenance item as the age creeps up on the car. Also I sprayed the heck out of this area with CRC brake cleaner to clean up the grease and antii freeze that was all over the engine. As I understand Junks comments he used a cleaner to clean his engine and his problems started. The common denominater I see here is we both used a solvent that could have removed what ever was used by GM for the heat sink. I hope this is the case since it certainly would be cheaper then a new opti

Yes, John, the IM sits under where the ignition coil is mounted on the front right side of the engine. The Opti ignition wire goes to the ignition coil.

I use brake cleaner to clean oil off of engines all the time. I only spray it on cast iron, metal & aluminum. I never spray it on rubber or wiring or connections as junk mentioned earlier.

I think you have found your problem.

SAVE THE

 

[LT4man]

Take a look at this

What does it say, John? I cannot read the page.

Thanks!

SAVE THE

 

[LT4man]

PS Mine is still running Perfectly this morning!!

Congratulations, junk!

Have a safe trip when you deliver the Vette!

SAVE THE

 

[John Robinson]

What does it say, John? I cannot read the page.

Thanks!

SAVE THE

It says that you have to put a special silicone grease on the IM back and on the heat sink back to help with heat dissipation. I went and got some dielectric silicone and put it all over the IM back the heat sink back and the back of the bracket to the head. I am putting it back together now but won't get it finished until later today. Time to run the wife to the doctor she had a total knee replacement on Oct 16 and the staples come out today.

I hope to re-fire the engine later today and see if this helps. When I removed the IM and Coil there was not any grease on them.

 

[gmjunkie]

Congratulations, junk!

Have a safe trip when you deliver the Vette!

SAVE THE

I won't be doing nothing but driving it now for a while,the dude bought a another car!!:L:L:L

 

[John Robinson]

Administrator Help

First I would like to ask an administrator if they could move my posts to a new thread for my problem. I feel as if I may have :hijackToms94 thread and I certainly do not want my issues to interfere with Toms94's original problem. His problem is his and I should not have started to bring my problem into his Thread. So in the interest of good forum protocol and manners please either move my subject or remove it from Tom's94.

Toms94 I hope by now the mechanic has had a chance to work on your car and that it is running great.

As for me the heat sink grease did not work so onto trying to pull the wires as it runs to see if I can isolate which cylinder(s) is not firing.

 

[Toms007]

John, I don't feel like you or anyone else hijacked my thread. The issues are very similar and this kind of consolidates the possible solutions and troubleshooting of those issues. But if you want the admin/mods want to move your posts I understand, but don't do it because they have hijacked this thread.....they have not.

I didn't hear from my mechanic yesterday, I am not going to push him, he's very thorough and methodical. And he is going to track down my leak issue which may slow down the reinstalling of the new opti.

 

[John Robinson]

John, I don't feel like you or anyone else hijacked my thread. The issues are very similar and this kind of consolidates the possible solutions and troubleshooting of those issues. But if you want the admin/mods want to move your posts I understand, but don't do it because they have hijacked this thread.....they have not.

I didn't hear from my mechanic yesterday, I am not going to push him, he's very thorough and methodical. And he is going to track down my leak issue which may slow down the reinstalling of the new opti.

Tom

My only concern was that I might have overstepped correct forum protocol and what makes this forum better then the others I have visited is that all problems and discussions are handled with respect. I agree the problems are similar and that is why I have been so keenly interested in how it turns out for you. We here are all professional in our behaviour towards all the members and there input and I never want to see that change.

John