Sputtering & back-firing
 

A new thing I have discovered with my car is it holds no power above 3k RPM's. It will buck & backfire, and not do anything. The problem is its inconsistant. The past few days, if I let the car warm up properly, its fine. But if its running cold, or too hot, it does this ****. And today it got to the point where the car doesn't even want to drive. It started constantly backfiring.

Its a MadZ28 tune for 91+ octane, and so far Ive only gone to one gas station for there Ultimate 93. Any suggestions?

Tommorow Im going to check and change my spark plugs & possibly even the wires. If it continues tommorow, are there any suggestions to what it could be? Bad mass air sensor? Poor tune?

Any codes?

- Justin

hmmm, i dont wanna compare lol, but my buddy with a mustang had similar problems. his MAF was dirty. i cleaned it up with some q tips and alcohol. another friend with a mustang had TPS problems and that sounds like it could be it too, or maybe it jumped time? start with the basics tho, scan for codes and work from there!

Well as far as a check engine light, then no.

I don't know how to read codes off the car.

Possible fuel delivery issue...maybe the pump is going? I suppose if the TPS had a dead spot or a two it could cause it...MAF could if its dirty like Ron said...

if youve got a schrader valve on the fuel rail (i dont know if LT1s do or not)...put a fuel pressure gauge on her while youre driving...and watch what happens when it starts to buck and what not.

And I don't know much about opti-spark either but couldn't that be a problem?

I'll check everything you guys mentions, anyones guess is def better then mine :lol:

The thing that bothers me is how its in-consistant.

Opti? :lol:

How new is the opti?

its a brand new summit unit. Full system. I let the car warm up this morning for about 10 minutes, drove it and everything was fine.

Saturday was the worse it has ever been with back-firing.

Fuel filter almost clogged - jz