Muscle Freak

OK so the car: 1994 Camaro Z28, Lt1 350, automatic trans. STOCK
problem: Misfire or hesitation
what we've done:
somebody put bosch+2 spark plugs in it, and 3 were cracked. so we put new AC Delco Platinum plugs in it. NEW wires, new starter (housing was broken). Removed AC compressor and replaced with bypass pulley.
It's got a hesitation or a miss at idle and when On the gas. Catalytic converter is making noise (THIS noise is consistent with the miss). Engine shakes when it's missing, as if the timing was off a little bit. OPTI is clean and dry, looks brand new really. Igntion coil and module Tested GOOD.
so what am i missing here? Help! Please! I'm not looking to throw parts in it just because, this is a customer car and she is on a limited budget. I am only looking to replace any parts that are causing the problem. That being said, i do NOT want to hear "Well change the opti, it probably needs it anyways", the opti is NOT the problem, car starts right up as soon as i hit the key.

CamaroAJ

iTrader: (3)

find what cylinder is misfiring check for injector pulse. then swap fuel injectors with a good cylinder and see if the miss moves.

msydow

try checking cylinder temps at the exhaust manifolds. could help in pointing to a dead hole. have you checked the pushrods? does it miss under a load also?

Muscle Freak

problem diagnosed as the optispark

Z28/2002

iTrader: (27)

I was about to say to change the opti

Muscle Freak

yea we went through everything else. new plugs, coil and module tested good, hollowed the cat, cleaned the MAF, wires are new...opti is the only thing left with the exception of internal engine damage

myk

iTrader: (4)

Freaking opti's man. Where are you planning to get yours? There's more contraversy about where to buy opti's than there is about health care reform. Let us know where you get it from.

You didn't get any codes or anything, did you?