Questions and Answers

Chevy Cavalier Blows Ignition Coils Q. Vincent, I have a 1990 Chevy Cavalier that I use as a winter 'beater'. It has a 2.2 liter 4 cylinder OHV engine with automatic transmission and the DIS Ignition. It has approximately 170,000 kilometers and the TBI fuel system. The problem started actually last spring. I pulled out to pass a car and immediately lost power and had to pull over to the side of the highway.

I tried repeatedly to start the car but had no spark. I could smell gas fumes. I had the car towed home and left it till about two weeks ago when I tried to get it running again for the winter. I moved it into the garage and did some checks. I measured the secondary resistance of the ignition coils and they appeared to be open.

I purchased two new coils and measured the secondary resistance and they were approximately 6-8k ohms. I installed them and tried starting the car; but it wouldn't start. I measured the coils again and they were open.

I went to an auto parts store again and this time I bought the two coils mounted on the ICM (Ignition Control Module). I again measured the secondary coil resistance of the coils before I installed them in the car and the were again approximately 6-8k ohms.

I also bought new plugs and plug wires and installed them along with the tested ICM and coils. I must say I was very gun shy at this time because I felt like I was throwing good money toward bad. Anyway, I attempted to start the car and after about three or four minutes it started; but was running very rough and I could smell very rich exhaust fumes.

I shut it down and again measured the coil resistance through the plug wires and they were open, but the car still starts and runs very rough and smokes a lot.

Question: what is causing the coils to blow and what can I do next to cure this ignition problem? Any help would be greatly appreciated.

Thank you,
Bryan

A. I have never seen this happen to a Cavalier! The ohms reading is correct, 6-8k ohms. Have you checked the Crank Angle Sensor (CAS) for A/C voltage while cranking it over? Is it possible that the crankcase is full of fuel and making it run rough?

Are you using GM parts for the module? I haven't had much luck with non-GM modules. Also make sure the harness from the CAS to the module is not oil soaked. Last thing is to put a scanner on it to see if any codes are stored or the data from sensors is skewed.