I'm still having this issue where after my car warms up it studders, loses power. Kind of sounds like its misfiring. I have changed the spark plugs and had the ICM tested. Not sure what this could be. I had it scanned and it show no DTC's. I want to check my coil packs to see if they are the issue. I tried looking through the site for the answer but couldn't find it. Can anyone tell me in detail how to test the coils because I have never done this before?

 

Part 1 -How to Test the GM 3.8L Ignition Coil Packs.

 

Hey peter x thanks very much..

 

Most of the time when a Gm coil fails it is because someone ran the spark plug wires too long. Plug wires should be changed 6-7 years.

 

Keep us updated I'm having same problem fyi I changed coil packs ,firing plate,wires ,plugs,cat delete just got my cdl permit today and gonna have to drive some distance to get experience plz help sorry to post here but same issue .

 

Just remember the result is a lack of good combustion in the cylinder. The reason can vary but the symptoms be exactly the same. If it a blown head gasket allowing the coolant to short out the plug, a broken ring or bad valve that will not allow compression to build, or a weak injector that will not give the cylinder enough gas and about 20 other things. They all result in the same thing, a misfire. Some engines are prone to certain problems but any one of the issues can arise in any motor. When it comes to engine “drivability” seeing what someone else did to fix the “same” problem can be a waste of time.

 

You know alot more than I do lol.. My buddy lent me his timing light so when it is messing up I could hook it up and test the wires.. While I did that I was holding the inductor in one hand and grabbed a spark plug wire with the other and the light started to flashing, like the current was passing threw me.. Doesn't make since.. Thought that it may be messed up and tried it on my dad's truck and didn't get the same result.. Any ideas gorn?

 

The test with the timing light means nothing. Those old timing lights are very touchy even a small amount of static charge to set it off.

Did you follow the tests in the above link? Those results will help figure out what is going on.

 

No I haven't done those tests yet.. Can the coils just mess up if they get overheated or is it that they are either good or bad? I did change out the spark plug wires today which didn't change anything.. Should of tested the coils while I was doing that but didn't have the time.. But as of now I have changed the spark plugs, the wires, and had the ICM tested..

 

Yes, a bad coil can start out cold working and acting like it's just fine, then start to overheat and cause the engine to crap out. Then you restart the engine after she cools off for a while, and the same cycle starts all over again. If and when you do the coil test, make sure you check them after the engine starts running badly.