When I down shift and hit high RPMs I sometimes get a backfire or a putter. The car has 70,000 but it had a full tuneup at 60,000, a new optispark at 40,000 thanks to a large puddle, an oil change 1,500 miles ago, a new K&N installed 1,000 miles ago, and I only put Mobile One and Exxon Super in her. Any ideas what I'm missing here or what may need adjusting or be defective?
Thanks
92TripleBlack :cheers:

 

I had a rumble from my Borlas on deceleration. A new opti-spark just went in and now it's gone and the mileage is better too. I kind of liked that noise but a backfire or a rumble is not good they say.

Look at it now when it's running with the hood open in the dark for sparks.

You can always have it put on a scope. That will save a lot of guessing.

 

Thanks Don. A scope wouldn't hurt. Can you tell me how or do I need to give the big blue bowtie a ring?
Thanks
92TripleBlack :cheers:

 

I had to go to a dealer in the end. I thought I had a skip so I read all the stuff here on the opti. and even downloaded it on floppys. I talked to my buddies at the hobby gargage where we fix my cars at night. They talked to their friends at a dealer. They were told to stay away from the opti.!

So a guy was found for me who had started his own business, who was a top electrical guy at a Caddy dealership. He knew the LT-1 inside and out as some Caddy's had them. Right off he would not just replace the opti. (that's where my mind was at that time). He said he would scope it. So I left the car there and he got sick, then he was so far behind, then he gave me another date weeks away. By that time the car broke down and I brought it to a dealer. They "tried something" and it didn't work. (they don't know what they are doing there).

So I went to the Chevy dealer in the next city. They are on top of this stuff and now it's running fine. Of course lots of my money is gone now.

Go to the closest dealer and talk to the service manager. If he does not know the Corvette and slips up with what he says then look elsewhere. If he does or introduces you to who he says is his Corvette expert then go with it. In the end it will be worth it. They may find some other item that effects safety for instance and point it out.

Did you look at it idling in the dark? Maybe it's something simple like a wire that fell off. I usually reach around the engine and twist all the ignition wires to make a new contact surface. How they feel is important. Just do the ones that are easy to reach, you may get lucky.

 

Thanks Don. I'm in the process of funneling every dime I have to a new set of rims and front brakes at the moment (I'm upgrading to C5 brakes and GS rims) so I'll check what I can and if I can't get it I'll stop by the old Malcolm Konnor (Paramus Automall) and see what they can find. They specialize in vettes. It doesn't seem to be anything but an annoyance right now and the other parts are safety issues I need to resolve first before paying out the cash. If it is the opti, I want to be able to tell them to replace it with the newer version so its a little more sturdy. I'll need a few more things then as well to make the newer one work. It just doesn't end. But that's OK
92TripleBlack :cheers: :smash: