I have a 94 z28....I recently did a head job and car was running GREAT ! ! ! Now all of a sudden one day i got in and drove it and when i was at a light it was running ROUGH.... motor was shakin so bad made my exaust rattle.... ANy suggestions????

 

Maybe it caught a cold? ;-)

Have you tested the fuel-pressure recently?

 

If the check engine lite is lit take care of the trouble codes first. If not, the ignition would be the first thing to look at. Check or replace plugs an wires for a start, and then look for other possibilities, like ignition coil module and ignition coil. The optispark would be the next choice, but due to the cost, check out the various sensors (MAF, IAT, ECT, O2). Then check the FI system,(Fuel Pressure & pressure reg &verify all injectors are firing. Finally take a good look at the Optispark.

 

Pete, you should make a "Pete's Guide to Ignition Problems" and sticky it. Have a little guide of all things to check and possibly replace to solve the problem. This question gets asked far too often, and you're the man when it comes to it. Then when the question gets asked because people don't look at the stickies, we can just link them...c'mon

 

Ok thanx for all the good information ! ! ! !