Intermittent Loss of Spark to 2 Cylinders

[Jeaniewats]

Hi,
I'm brand new to this site. I see many of you have a lot more knowledge about cars than I do.

I can drive my car once a day, when it runs beautifully. It's a 1993 Cavalier with 190,000 miles. As long as I don't have to stop and restart it, it's fine. Once I've turned the car off, it misses on 1 and 4 when I restart it, even if I leave it sitting for 3 hours. Once in a while, it tricks us and will restart well 4 or 5 times. Other times, it "fixes" itself while I'm chugging along on 2 cylinders and surges forward. Luckily, I stay well behind the cars in front of me. Still, it's dangerous, but I use a wheelchair and can't get around any other way.

After pulling the plugs (they were okay, just normal wear), and changing the wires (which were original), my friend, a mechanic for over 30 years, changed the coil pack, which did no good.

It's obviously an electrical problem, but it could be the crank or camshaft sensor or the brain, right? Is there anything else you can think of? While going through the website earlier, I saw a section showing how to check the crank and camshaft sensors, but now I can't find it. I was also thinking it could be a loose or broken wire from the ignition switch to the coil pack, but I'm not even sure how they are wired. (It's been over 25 years since I worked on a car, but I remember fixing someone's car once where a wire to the coil was broken inside, and the insulation looked fine, and his problem was similar, though he stalled out).

Any suggestions or tips will be greatly appreciated.

Jeanie

[J-Ri]

More than likely it's the ignition module (the thing the coils mount to). I noticed you said you friend changed the coil... there are 2 coils on this engine, one for cyls 1,4 and one for 2,3. If only one coil got changed and it wasn't for the misfiring cylinders, it could be the other coil too. I would strongly reccomend against driving it at all if it's misfiring when you start it up, runing without spark dumps raw fuel into the exhaust and will destroy the cat.

The crank sensor is mounted to the ignition module and there's a good chance it will break when you pull the module off, they get brittle with age. If it breaks off, it's a PITA to get out if you have an automatic transmission.