My 1998 Catera started to give me Cylinder 1 misfire recently. Here is how it happens:
The car starts right away each time I crank the engine. Sometimes when idling, sometimes just after I start accelerating, the CEL starts flashing for about 5-10 seconds and then stays ON. Almost all the time during the ride, I feel the engine is rough, and if want to accelerate I hear a very loud noise, and shaking on the engine. If I release gas pedal and push it down more (faster acceleration), the engine seems to be doing better, but still after some time the loud noise comes back.
I have checked the spark plug on the Cylinder 1, looks OK. No oil around the tips. I have checked the wire connections, but did not do any measurement. My mechanic told me that the coil pack might be bad, but I am not sure (nor is he).
What would you recommend, or any other idea from the experienced people here.
I would think it's one of 3 things....plug, wire, or coil. When I got my Cat, It was misfiring on 2 cylinders. New plug wires fixed my problem. They're not cheap, but nothing on this car is.
I had the same problem a couple of months ago. I had changed the plugs and wires but the problem was still there. After i changed the ignition coil everything became normal. So i suggest looking for a new ignition coil maybe from ebay or from a junk yard.
