i have just recently replace the ICM on my car 3 times in the past week and a half. when i got finished putting my new motor in i replaced everything that could be replaced including a new ICM it drove for about 3 days and it just died while going into town,i let it cool down tried to start it and nothing just cranking. just guessing i put a new ICM in it started right up. the next day it did it again, replaced it once more started right up. dove it for a full day. the next day it died about 3 miles into to my trip. what could be causing them to go out so often?

 

In order to fire the coil, the ICM momentarily pulls the 12 volt source thru the coil to ground. Many devices like a coil or motor that is composed of coil windings, over time begin to experience adjacent coils shorting together. This internal shorting causes the device to draw more and more current. If the coil is "shorting" internally and it's current draw is increasing, it could in theory kill an ICM. Incidentally the coils used on these vehicles are considered "tune-up" items and should be replaced periodically.

If you see tell-tale white spots on the black plastic insulation of the coil, this is a sign of shorting (in a way) and should be replaced. White spots or not, try the coil.

 

im sorry i should have said that it is a brand new MSD coil

 

So?

 

i understand... thank you

 

If you can get a replacement MSD that's ok but I would buy a cheap replacement from AZ or advance and try that. I don't know that much about MSD coils but what if it's made to use near the upper limit of current from the ICM. If you simply get another and it does the same thing, you will be on a wild goose chase to find the problem.

Were as the cheap OEM style from AZ or the like will answer the question real fast and costs less than $20 to put the question to bed once and for all.