I started my car cold and drove about half a block when it started running rough and the CEL came on flashing. I drove back home and shut off the car. After waiting about two minutes I started the car again and it was still running rough with flashing CEL. After the car sat for about two weeks (while I looked for my diag cables) I read the codes and found cyl 1 misfires. I checked the plug wires for security, looked for obvious plug wire damage and found nothing that looked wrong. I started the car and it ran smoothly with the CEL on steady. I cleared the codes and it didn't immediately return. I revved the car to 2000 rpm and then 4000 rpm and held for a few seconds. The engine ran smoothly. I drove the car to work (33 miles of freeway each way) and just as I returned home the CEL came on steady. Again with the cyl 1 misfire code.
Car is a 97 C2S with 98,000 miles. Steve programmed the ECU for me. The plugs, plug wires, caps, rotors were replaced for the second time (engine out) Jan 2011 at about 85,000 miles. I have owned the car since 2005 when it had 45,000 miles. As far as I know there has not been any fuel injector maintenance.
My amateur theory is there must be an intermittently shorted plug wire or a problem with the fuel flow at the injector. Or possibly a valve train issue? This guess is based on the misfire only occurring on cyl 1 and being intermittent. I think this makes the flywheel sensor, coil, coil wires, caps, rotors, plugs unlikely to be the cause?
The only way I can think of to troubleshoot this is to replace the most likely part and drive? Is there something that should be done with the fuel injectors? Any suggestions?