just sharing my story..

i have a 94 Z28 Camaro that runs great, but 8 months after i bought it.. My car started having problems.. Went to Felix Chevy (Dealership) to get a computer diagnostic and they said my Opti Spark was crapped out but they needed $1,500 to fix it (never) . So let me tell you what happens to my car... car cranks up fine, when its cold, drives like a beauty... when it starts to warm up.. it will get really ruff on the idle, if i throw it in Neutral and press on the gas a lil bit i can get by at the stop lights, but a lil while after that it will start to cough when i try to drive it... Does this sound like an Opti Issue?? Just bought a new Opti Spark on EBAY for $288.00 brand new so hopefully everything works out..

Other question... Should i buy a new water pump even if my current waterpump doesnt leak? (Dont really have the funds for the waterpump right now) .. help lol

 

sounds like opti to me once it gets warm the tolerences change and it cant read the way it should

 

Sounds a little bit more like o2 sensors to me. Just throwing it out there.

 

yup i actually got 1 of my o2's changed.. but the mechanic wanted to charge me an extra $120 to change the other 1.. i live in Cali so its ruff man lol.. but **** na, so im rollin w 1 old o2 and 1 fresh... but when i have the opti installed ill just have the mechanic put in the other o2 sensor

 

Yea on stock manifolds its a pain in the butt to change out them o2's. But I really think it would help you out changing those.

 

Check for air leaks after the MAF. My old transam ran fine when warming up but in closed loop it ran like hell. My intake elbow had a crack in it letting unmonitored air in. In open loop, computer doesn't use MAF readings I don't believe.

 

How many miles on it?
Its most likely your cap and rotor need replaced.
The new opti should fix your problems as long as it came with a new cap and rotor.
You can reuse your old waterpump but since its going to be off anyway......
If you want to find out if your O2s are bad just hook up a scanner and watch the counts.

Just for the record, this is exactly the way my car acted when the cap and rotor needed replaced. The bearing in the opti wasn't great either so I opted to replace the whole unit.

 

Are you absolutely positive it doesn't leak? The reason why I ask is the same symptoms happened to me. Found out that only after the engine would get warm it would trickle coolant out of the weephole just enough to screw with the opti. The only way I found out it was leaking was by mere chance. I jacked up the car just after running it to operating temperature in getting ready to take the opti off and saw a small stream originating off the weephole.

 

I bet it's the ignition module. Once it warms up, car runs like crap. Seen it before posted here many times. I have never heard of a cold/warm condition related to the distributor. I spaced my module out away from the head so it stays cooler.