Common cause of coil pack/transister failure

[t4-teg]

First of all, Im not sure if this is the right thread or not, so mods, feel free to move it if needed.

On my car (90 1G) a few weeks ago I was driving down the highway and the car just died, and wouldn't start. I replaced the Coilpack, and it still didnt fix the problem, so I then replaced the ICM/Transister, and the car drove/started/ran perfect until yesterday.

My car drove fine to work then at lunch I got in the car, and it was only getting spark to cyl's 1&4. So I replaced the coil pack again (under warranty), but im trying to find reasons why the coil packs/transisters fail on our cars so much. What are some leading causes, ive heard loose connector to the ICM/transister as well as open wires in the ignition circuit.

Will a open injector wire cause this? I have noticed in my car sometimes the car will sputter and run on 3 cyl's sometimes, and ive traced that down to the wires going to the injector clip on cyl 3. If it starts sputtering/missing, I can wiggle that wire on injector #3 and the car will run fine. So I pulled back the insulation(which was all cracked and broken anyway) and noticed one of the wires was missing some insulation in one spot. Im guessing this was grounding out on something? IDK, but that does sound like something that would cause the coil to fail, Especially the coil for cyl 2 & 3, since the injector with the broken wire was #3.

Im just trying to get a good discussion going on causes and possibly cures/foresight's for a failing coil/ICM.

 

[big_d]

The first thing I would do is replace all of your injector harnesses. I always seem to break one when I replace injector seals anyway. Another thing you might want to take a peek at is your ecu. You never know what it may look like seeing that it is a 90.

 

[rich3389]

Bad spark plug wires (magnecores) made my car melt 5 coil packs until I changed the plugs.

 

[MichaelSuch]

I just lost a power transistor on my '90 right after installing my tach noise filter. I didn't have an intake manifold support bracket to where it bolts up from the factory, so I just bolted it up to where the ground wire is on the top of the intake manifold. My tach was finally working then, and 5-7 seconds after it was running it shutdown like it ran out of a fuel, but it's getting no spark...

I too have a few injector clips broken off, I'm not sure if that's the reason though.

 

[t4-teg]

Bad spark plug wires (magnecores) made my car melt 5 coil packs until I changed the plugs.

Good to know. Im somewhat doing a whole ignition system overhaul, so wires are next on my list.

My ECU is good though, the caps were replaced a few months back, and everything looks perfect in there.

 

[MichaelSuch]

I have new NGK wires with less than 500 miles on my car, I've got another power transistor coming in and we'll see what happens.

 

[DSM Jeff]

I have had some similar issues. At one point in my old 91, the car started running on cyl. 1-4. First thought was the coil pack died but that wasn't it. Turned to be the ecu which was already rebuilt. I was told that there are capasitors that deal with the coils (not sure on this) but one wasn't replaced. The shop took care of it for free, but that was one issue for me.