Have toasted 3 now to date in 2 years and the frequency of the failures keeps closing up. From my research on this site the suggestion is wrong plug types can cause this? I have replaced, coil, leads, distributor and continue to fry them. The plugs that the car came with and is still running are NGK BP5FS and I think could be the problem as they are non resistor. I have ordered a set of AC Delco R45TS plugs which are the recommended ones in my manual and am hoping this will sort the problem.Am I on the right track? Is there any other causes of this issue? Seems odd as my 85 tpi Camaro will run any plug in the right heat range and give no issues but its the large cap HEI and the 88 Iroc is small cap, two different modules. Thanks for any insights into this

Simon

 

When you have reaplaced the ignition module you are using the die electric grease that should have came with the replacement module and also make sure where the module mounts in the distributor is wiped clean of old grease. Heat is a killer for these. I am using the same NGK spark plugs you had in yours and have not had any problems.

 

Hi Irocblast, yes am using the dielectric grease, cleaning area underneath etc etc and the car runs perfectly until it fries the module. last one lasted 4 months, and there is no lead up issue for when it goes out.The last one died after being parked in the garage after being used and there was no spark the next time I went to start it, so annoying as you never know when it will fail.
Cheers

 

Best to use heat sink compound, not dielectric grease.

Be sure to use only GM AC Delco ICMs.

A bad alternator or loose battery cables can take out an ICM. It is from excessive voltage spikes.

RBob.

 

Some aftermarket "high voltage" coils can cause ICMs to fail by pulling too much current through them. I also read somewhere that stock coils that are in the process of failing can fry ICMs.

 

Also a bad Engine Ground will do the same thing

 

Will check the grounds and battery earthing etc, never had any problems there. Am running new stock coil, ac delco stock module and have just ordered some heat sink compound to go under it. Am thinking about setting up a computer fan and duct cool air to dizzy to see if this will help as these are hot running engines at best.

 

Just had a thought, the A.I.R pump is still there but disconnected. It would be real easy to run a hose from it and constantly blow air onto the rear underside of the dizzy to cool the module to see if this gives it a longer life?