blowing spark control modules
#805268 July 27 2023 2:35 pm OP
wzard1
stranger
W
Joined: Jul 2023
Posts: 6
Likes: 1
1987 gmc vandura 2 wd 350 throttle body.
Can't go 500 miles without blowing a spark control module.
What I have done.
- replaced the control module 5 times.
-external coil 2 times
-coil beneath the distributor 1 time.
-plugs ,cap and wires....all quality components.
-new battery and cables.
This van has 152000 miles all highway.
NO rust! Always garage kept and in great condition.
This is my traveling van and now I am afraid to go around the block.
Just today it shut down in the driveway after idling for 5 minutes.
There are no mechanics around here that are old school and can trouble shoot this problem.
I am at my wits end on this.
Up till this time this van ran flawlessly.
This problem has been going on for 4 years now.
If some one knows or has heard about the fix for this problem, please let me know. Tim.

 

1987 gmc vandura 2 wd 350 throttle body.
Can't go 500 miles without blowing a spark control module.
What I have done.
- replaced the control module 5 times.
-external coil 2 times
-coil beneath the distributor 1 time.
-plugs ,cap and wires....all quality components.
-new battery and cables.
This van has 152000 miles all highway.
NO rust! Always garage kept and in great condition.
This is my traveling van and now I am afraid to go around the block.
Just today it shut down in the driveway after idling for 5 minutes.
There are no mechanics around here that are old school and can trouble shoot this problem.
I am at my wits end on this.
Up till this time this van ran flawlessly.
This problem has been going on for 4 years now.
If some one knows or has heard about the fix for this problem, please let me know. Tim.

 

Welcome Tim - I assume you are talking about the ICM inside the distributer - heat is it's enemy. Install using lots of thermal paste. My 93 Sub goes thru one every 70k miles or so.

 

Check all your grounding points. When there's no place for the spark to go , it starts misbehaving and taking shortcuts, frying everything in its path.
While you're at it, replace the engine ground strap. If it's the original 40 year old one, it'll be pretty rotten.

 

Ya, that's the one.You think that is all there is to it?

 

Isn't there supposed to be heat transfer compound under the ignition control module? Did you put any there?

 

yep gotta put the paste on or it can't dissipate heat

 

So where do you apply the paste? Got a picture maybe?

 

I am not sure...it's been awhile since I looked under the cap. Doesn't the part come with some to put on? I assume that a mechanic did so when I broke down on the road. Others have asked me that question. Do you think that this is the sole problem with my dilemma?
What about the HKR unit under my drivers seat? what's that do? Its laying there right beside the ECM....

 

The ICM mounts with two screws inside the distributor - you should have thermal paste supplied with the part, just slather the entire underside well where it contacts the distributor.