I have a 95 z LT1 4L60E with 166K original miles. Lately the car has become harder to start and it then runs very rough (missing) for a few seconds then it clears up and runs like a good old LT1 should run. As an fyi I had replaced the opti cap and rotor in its younger years and recently replaced the fuel filter. The fuel filter was in good condition considering the mileage. Performance is there with no observed anomalies. I heard of users getting a many miles off their Opti and others getting very little. Any ideas. Thanks John

 

check your codes and if you get code 18 which is a low or no crank signal its your ignition switch. i was having the exact same symptoms as you did and couldnt figure it out... replaced the coil then the module and still didnt solve it. i had a newer opti on it so it really shouldnt of been that but ended up doig some research and heard that the ignition switch can cause you some messed up opti sypmtons. its located on top of the steering column and is a bitch to do. but either way i pulled it off and it was completely burnt. hence why it was hard to start as it wasnt getting signal or very little and causing issues when cranking over.

give it a shot... i havent had a problem since.

 

Great and Thanks, I will get it scanned tonight. My symptons are it cranks easy but sometimes hard to start ie., second or third try on the key turn. Then when it fires up it will run rough (missing), and after a few it will clears up and runs fine with out issues. It doesnt do it every time but it has been getting more common. 'Hard to believe its the ignition switch but you never know. Thanks again. John