hello my car is 1991 camaro lb9. I turned the car on in the morning and let it warm up of for 13 mins and i drove it for like 2 mins around 25mph and the car just completly shut off while driving with no warning or any signs. I managed to park it on the curb but now it wont start. I hear the fuel pump humm when the key is on. The engine light wont turn off and im not sure if its the ignition control module because ive had to replace it twice in the past. It shows the same symptoms of cranking but not starting up. The last time i replaced the ignition control module is about a year now. Any ideas what could be causing this? any advice would be much appreciated

Thank you for your time

 

Sounds like ignition module.

Could be caused by using cheeeeeep ones, not putting the right heat sink compound under it, or various other things, but those 2 would be my 1st guesses.

Regardless, troubleshooting a no-start is kind of a no-brainer. It takes 3 "magic ingredients" for an engine to run: compression, air/fuel in reasonable proportions, spark at about the right point in the engine cycle. THIMK: it probably didn't lose compression all of a sudden, with the possible exception of the timing set, so it's probably not that. You can smell fuel if it's being injected, or substitute with starting fluid, to rule that out. If it's not those 2 things, then it's spark. And I'd start working on that, at the module.

 

I recently found out that most of the heat sink that comes with the igniton control module isn't the correct one to use for the application. Every time ive replaced it I've used the supplied heat sink instead this time I'ma use a good quality heat sink instead and this was a ac Delco control module

Thank you for you time

 

That would explain that...

I keep a giant tube of Dow-Corning 340 for such things.

 

this. so much this. Same thing happened to me a few years ago (there's a couple threads of my frustration floating around here).

glad you got it fixed.

 

Thanks everyone for the help , replaced the ignition control module and she fired right up.

 

 

I wouldn't doubt there was once a time someone extended the wiring on the ignition module and moved it somewhere other than the back of the motor. Somewhere nice and cool.

 

Sounds like the beginning of a story. . .
"Once upon a time, someone, somewhere extended the wiring on an ignition control module and moved it. Moved it from the sweltering, clustered heat of the back of the engine, to someplace else, someplace. . . .cooler."

*explosions and guitar solos followed by fast paced action sequences*

 

This has been done. Still need to heat sink it with a chunk of aluminum, and ground the heat sink to the engine block. The wires from the pickup coil to the ICM should be twisted together.

I've added a heat sink to the distributor base right under the module. That too is helpful.

RBob.

 

Id like to see some pics if you have any.
I understand that GM found it convenient to put it on the distributor housing... But I would think after about the 3rd or 4th year into the design, when the dealerships are all complaining about failures, GM would relocate. I suppose spending several hundred thousand to modify their assembly lines was more expensive than the more vehicles they would sell.

 

Bad news everyone , so orginally the first icm went bad on Friday and I managed to fix it on the weekend, and now today in the morning at 6am it decided to go out again,so I managed to buy another one and fix it after I got out of school and she fired up sounding healthy, so I park and in the night on my way to work it decided to go out again, so now I just replaced it again with a ac Delco and proper heat paste and now the car is limping like if it wants to shut off and has no power, I'm thinking the problem might not be the icm but something else that is frying them up, the previous one only lasted a few hours, I really need help deciding what to check or fix next.

 

Check the cap & rotor for a carbon track. If the spark goes down the shaft or tracks over to the base plate it can take out the ICM.

A bad alternator can also take out an ICM.

A bad ignition coil can also take out an ICM.

RBob.

 

In this thread:

https://www.thirdgen.org/forums/v6/1...-why-does.html

RBob.

 

Thanks for the replies, I've read from the post that he finally fixed his problem by replacing the alternator, maybe the alternator is frying up so many icm in my car. Other users also mentioned to replace the whole distributor and that had fixed there problem aswell. I suppose I can take the alternator to get checked at AutoZone and if it checks out good then I might have to move on to changing the distributor.

 

Like Rob said, back up from the ICM and check each component. The proper heat sink grease will help them live for a while but if there's an electrical gremlin it will still kill the icm eventually.

A good example - a bad icm can put stress on the coil. . .an underperforming coil can kill an icm. . .which then damages the coil further. . .it's a bad cycle.

Thankfully you can bench test all these components with a multimeter.

 

Also - check all your grounds and make sure they are secure.

 

Around the first time the ignition control module went out I first thought it was the coil so I purchased a Accel coil about a year ago. Maybe it would be best if I replace it as well? I was reading on a fourm about Accel coil not being so good and killing the icm

 

Yeah, I had an Accel coil go bad and shortly after I had ICM issues. MSD makes a good coil.

 

So i had an old msd coil from last year, I stored it on the shelf and I decided to test the Accel coil and when I put the msd coil in the car wouldnt start at all but when I put the old accel back in the car started up but it idling very rough, some cylinders are not firing and it's stuggling to stay on so what I'm thinking about doing is buying a new coil and replacing the distributor aswell I already have the distributor in hand and I also have a new alternator in hand as well
what do y'all think it's making it run so rough ? This is the first time it's running so rough after 6 icm

 

Sounds like the old MSD coil was bad and the accel is on it's way out.

 

Good news, the car seems to be fixed now, after installing a new distributor, a new coil and a alternator the problem seemed to be fixed. The car runs good now and hasn't acted up since the fix. I think the problem could've been the distributor itself, I noticed on the two wires running from the pickup coil has the insulation peel off right under it and wasn't noticeable while it was in the car unless you had a mirror to see under the pick up coil, I was thinking it could've been arching and might be the reason why it took out the ignition module so often. That's just observation I made when inspecting the old distributor.

thank you everyone that helped, it was much appreciated