weinerschizel

You guys tell me what you think this is. I have a good idea but would like to see if you guys can confir first.

I was driving my Z28 w/ newly rebuilt motor today. It has about 2k miles on the rebuild with basically stock motor that has a CC306 cam. It was REALLY hot but car seemed well within temp.

Anywho after about 15 miles of driving it began to slightly sputter. It has done this very seldom before but I have encountered it ever so slightly once or twice before. Over the course of the next 5 miles or so it just kept getting worse and worse. To the point where the car would hardly go down the road. If I smash on the gas it just caughs and sputters.

I pull over on the side of the road at a gas stop and let it rest for 30 minutes or so while reloading stock spark maps w/ tunercat. After starting it back up the car would go down the road. However, if I would mash on it it would not pull over 4k RPM at all. Plus there was very limmited power a cruise w/ 60-70mph. Under accelleration it would again caughf but get up there.

What do you guys think this is? It was litterally like the motor was caughfing and would loose all power while doing it.

Thanks for the help!!!!

MonkeyManZ28

man i am having the same problem. i just had a rebuilt motor put in with the hot cam, ported heads, long tubes, roller rockers, etc. when i picked up the car it ran ok but through out the day i got the car back it started to develop a miss, then it got worse and worse, and worse to the point it was backfiring when it was idling and hardly would start. my car sat for about 7 months and i thought it had a little bad gas so i changed my fuel filter but didnt get better. this is really driving me nuts, i just want to drive my car. if you find anything out that fixes your problem let me know.

weinerschizel

Does this sound as though it could possibly be an issue with the opti spark?

CamaroSS30thAnn

same thing here.....no codes or anything?

im about 90% sure its my fuel pump......but opti could be a problem and well id say maybe cats but i c u have aftermarket ones......check ur plug and wores also...ur ICM may be getting hot an acting up ...tryteh cooling mod and c what that does

weinerschizel

Actually I have my fans hotwired on all the time. Just did a data run while going to the post office with it. Haven't got a chance to look at it in dept but after hitting about 4k RPM all i get is knock. The computer retards timing like up to 5 degrees. This is even if I rev it up under idle. I have yet to check the plugs and wires.

I have logged data with the symptoms if anybody wouldn't mind looking at it. Perhaps somebody know's more about the figures than I do. The PCM is giving me as much as 10 degrees of knock retard!!!! Yikes. If somebody doesn't mind helping us out that would be awesome!!

Thanks!

weinerschizel

Here's an update. I just put a new opti on. It doesn't seem to cut out now or sputter. Unfortunately though I still have lots of knock at WOT.