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Skipping, Misfire Problem

04GT2

New member
Back during the winter our 04 GT2 started having a misfire or skip of some kind after 170k miles or so. At first I thought it was a transmission problem, but turned out to be something engine related without any codes triggered. Our mechanic said maybe it's the ICM, and not knowing enough about how it all works I thought a cheap ICM from Autozone would help. We have the same PCM. The car just ran worse, with it dying and undriveable around town.

I could pedal it like a dragster, and get it to the GM shop where they flashed updated software. I don't know if they flashed the PCM and ICM, or just one module or the other. It still had a skip or intermittent hesitation at part throttle so we had new iridium plugs and Bosch wires installed. It still had issues, with P1361, P1362 codes now tripped, and even a P1106 once or twice. We decided to get a grocery getter and leaving the GP sitting until Spring so it could warm up outside, and my ailing back could get better.

It was nice outside yesterday, and I decided to start the GP. I opened the hood, removed the plastic engine cover, and it fires right up, but I start hearing something funny. Sticking my head under the hood, I hear crackling and popping like arcing high voltage, but cannot determine where - seems like a front plug wire, but not sure. Damn! I wish it was dark outside. Starting the car again in the dark, there wasn't any arcing or popping, or anything funny. It started and ran fine.

I wonder if there's a bad coil, or if it was the routing of the plug wires causing something. I'm going to route them better than the shop did, and am also thinking of putting the original ICM back on. I'm also tempted to get a PCM from the junkyard, and maybe some coils. This whole thing is kind of baffling. Suggestions are appreciated, thanks!
 


I checked the routing of the plug wires & stuck them in the grooves where they should be, down front.

While in there the coils were checked & the original ICM was cleaned up on back and also the mating surface on the engine.

I used pins in the coils and checked the coils. The primary resistance and secondary resistances were
.3 & 5.54K Ohms
.2 & 5.46K Ohms
.2 & 5.37K Ohms

Taken at about 50 degrees. Haynes says they should be .5 to .9 Ohms & 5 to 10 k Ohms. I don't know exactly how much effect the temperature & the pins had on measurements.

After this, it ran and I didn't hear any popping or snapping noises. It's got new wires so they shouldn't be a problem

-- Sent with :-)
 
spray some soapy water around and you'll find the spark leak easily.

Why soapy? Regular water works just fine.... or are you suggesting he clean things during diagnosis? lol

The coil winding test can be misleading. Even if the coil has a break..likely when you test it....it'll test fine. Since you heard the arching.. wait til it's dark and mist the engine while running. Once you find it..likely you'll be all set.
 


If the regular water doesn't have enough particles in it it won't work. Like distilled water won't work for it
 
I found out how to find a spark first hand yesterday. Messing with my icm I pulled the spark plug wire off on accident and shocked the hell out of myself.
 


Did you ever fix the skipping problem?

We let the car sit. It was registered last week and it's being traded on a 40,000 mile 2003 Mitsubishi Eclipse today. This is my daughter's new car.

It was skipping a bit coming down and my wife (following behind) said it smelled eggy or bad whenever it did.

We put a lot of money in it over the years, and I liked driving the last time - so kind of sad to see it go. It was time though.

Thanks to you forum members for your help!

-- Sent with :-)
 
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