Originally Posted by Backyardjunkie

After buying a new optistart which came with a new connection harness which runs from top of motor under the plastic cover to the optistart.As I was unplugging the new harness connection from top of motor I noticed it was hard to unplug.I finally pulled it off.But after I went to plug in the new connection I noticed it wasn't lining up correctly.The plastic tabs that help line it up were on the wrong side...So I looked at the old one I took off the car and it was wrong also.I'm pretty sure this 1995 corvette has never had a tune up with 50,000 miles on it. I looked into the original connector and one of the four pins was pushed all the way back due to it being forced on. I was thinking how many Lt1 vetts have this issue.I wanted to share it.I took the new connector and took a box knife and cut to plastic tab off and then it fit perfectly into the boot.This wire runs the the top of your optistart.So having a one wire not connecting good will make your car run bad or skip. This is just a added problem of the optistart problems.But sometimes missed due to using the existing harness and not using the new one.I wanted to post what I found.This could have been a problem straight from the factory or from a bad replacement part.But like I said, its looks like nothing ever got replaced on the car. I replaced the optispark,harmonic balancer, water pump and spark plugs and wires. Check your connection harness under the plastic cover above your valve covers. This connection could be incorrect but still pushed in. Unconnected it and look inside and make sure it being lined up correctly and you can see all four connector wires inside. I hope this helps my fellow corvette owners. As we share it shows we care. Drive safe!

Originally Posted by C5 Diag

This is a 12 year old thread !!...I’m sure the OP has gotten it rectified by now.