maybe optispark???
 

ok i just got my car back from putting in a LT4 hot cam, headers, ported heads, exhaust, MSD cap and rotor, MSD plug wires...i got to get it tuned and my idle is jumping around and whenever you get on it sputters some...we get the idle right and now the car is really sluggish and sputtering more...we think the optispark is going out what do you guys think???? thanks...i have a 1994 Z with 125,000 miles

the optispark is never "going out". its either in or its out. you probably have the wires installed wrong or theyre not on all the way or possibly burnt. i kept burning plug wires on my 95 Z with headers. its a common problem with LT1s and headers.

Opti's can slowly go bad, mine did- but it was more at a cruising constant speed.

Sounds almost like a vacuum leak playin havoc. Do you have a laptop by chance? If so you can just pick up a cable for your car and use many of the programs out there to monitor whats going on with your car. It has helped more than once!!