alright...i have a huge problem that i need to fix before my car goes to get tuned. First off...the car just had a GM847 cam, stock ported heads, and supporting mods put on the car.

heres the problem.... The car was misfiring since i got it back, and I was going to run nitrous on the car...so i was just like alright...its probably just a bad plug/wire....so i put brand new MSD superconductor wires (8.5) with brand new TR6 plugs.

That still hasnt fix the misfire... So i didnt know what to do...i took it to chevy and they said they cannot find anything wrong with why it is still misfiring, and they think its just because the car is running so rich from not being tuned that its causing the misfire.

they also said its not a constent misfire...but when it does, its all 8 cylinders... could this be a bad opti? they said it was fine, but i cant see a car misfiring so bad just because its running so rich/not tuned


Sorry this is so long..but im really confused and i need some help

Any suggestions would help, thanks!

 

ttt anyone???!

 

I find it hard to believe it's all eight cylinders misfiring! However a scanner could easily confirm that.

If that is the case, you should start by looking at those items that are global to all cylinders.

You could have a problem with the ICM, coil or the coil wire to the opti.

If all those check out, start looking into fuel. See what the O2s are reporting. You may even want to pull the plugs and see what they look like. If you have known good spark components such as those listed above, and the plugs are black. Chances are that is running pig rich and fouling the plugs causing your misfires.

If you find that less than all 8 are fouled, you probably have a spark issue.

 

If I read this correctly, you are running heads and cam, but have still not had it tuned. Why not at least get a quickie mail-order tune, so you can get some idea of how much of the problem is due to "problems" and how much is due simply to the fact that is has never been tuned?

 

i never put a mail order tune on it, because the car was finished, then less then 2 weeks later it was going to be on the dyno for a tune, so i figured by the time i get the mail order its going to be pointless because its going on the dyno right away...but thats what im doing now...im just gonna mail order tune it...get it running close to good...then figure out the misfires

thanks