Ignition Module keeps failing

[COCJ5]

I bought an 83 CJ5 AMC 258 i6 / 4.2l I6 about a year ago with 75k miles. I had the first ignition module failure in about 200 miles. The second about 60 miles later. I didn't drive it much this past winter. I had one fail last week, replaced it and the new one lasted about 5 seconds. I talked to the previous owner and he said he had only one fail at about 55k miles. Does anyone have an idea what is taking these out. I have examined all the wiring I can see for any shorts and haven't found anything. The local auto parts guy suggested there might be a problem with the coil. Thanks for any advise.

Rod

 

[Torxhead]

From what I have heard two items can kill an icm are buying a cheap one and a poor ground from the icm. I purchased mine a N.A.P.A. and put out $80+. The ground is the black wire from the icm to the distributor. I cut the black wire at the distributor and ran it directly to the battery. Plus there is a spare in the Jeep. There are other ways to deal with this if you don't have to deal with emissions testing, but that leaves me out. The best thing to do is the MSD unit of course.

 

[COCJ5]

Thanks for the info. All the modules I have bought to date have been Motorcraft brand. I am not familiar with the MSD unit.

Rod

 

[Incommando]

Aaaaah hei chooooo

 

[Torxhead]

Bless you Incommando, another option is a high energy ignition distributor like a D.U.I. or a GM hei conversion, worth searching out. Also there is a "Team Rush" stealth hei module which like others suggested replaces the icm. None are emissions legal except a icm replacement for the later Jeep CJs. Also look up the "Team Rush" motorcraft upgrade which adds a larger distributor cap to help prevent spark arcing along with brass contacts for a better connection.