JesseMorales

I have a 93 corvette with about 155,00 miles on it. I have replaced the spark plugs, wires within the last year or so, and optispark last week. Some days the car runs perfect and every other day when driving she feels like she is running on 6 cyclinders with no power. I am not getting a service engine soon light. Could it be something else that is electrical and is so wouldn't it be running bad all the time. On days she is running good, I run it for about 30 min and give the car time to get to normal temps, so the O2 sensor should be working okay. Does anyone have any suggestions

Rex Ruby

If you just did the opti I would check all the plug wires that they are seated properly. Could be the coil, couldn't hurt to put a new one in with those miles. I would have your injectors tested. Could also be the computer.

runner140*

Any chance it could be a lazy/tired old fuel pump or a dirty fuel filter?
I went through the above with simular symptoms. It started with poor performance and got worse and then just stopped altogether.

coupeguy2001

It might be a partially plugged cat on one side, or maybe some other exhaust obstruction in the resonator.
I have a LT-1 exhaust for sale............hint

toptechx6

With that mileage how about the timing chain jumped a tooth??

fake

What is the history of the car? one owner what has been replaced in its life? Plus that is high miles and you will be throwing parts at it left and right! If it runs and goes forward just drive it because as you know parts are not cheap.

FAUEE

Did you pull codes? Just because you don't have a check engine light doesn't mean it doesn't have stored codes.

fake

My 1993 never throws a code and to prove it Opti was so rusty (16,000 miles) not one code and water pump so rusty channel locks would not move the spindle.This is one tough cookie to trouble shoot!