I have a Kenne Bell Charged Cobra with a JLT CAI, 2400 Mass Air, BAP, SCT tune for 91 oct. Car was tuned by a Kenne Bell autorized tuner with a SCT unit. It's making 15 psi of boost, 538 RWHP.

Here's the deal. IAC is new and the fuel pressure sensor on the rail was replaced 2000 miles ago. The car has a miss when idling. Its similar to when you leave it run and take the gas cap off, it starts really idling goofy then. Not sure if thats normal or not though, but with gas cap intacted, car misses. Had a reliable person at a Monroe hook a scanner to it to check for miss fires and the cars computer showed none. But, it said something about an ambient air temp problem. Is there a sensor for this because I never heard of it. The only thing I don't know about the car is what fuel system modifactions have been made other than the BAP. But it never has issues when driving or under load. I originally thought maybe plugs or coils but with no miss fires, I doubt that is my problem. Could it be the tune or timing?

Any help would be great.

 

Have you checked out the plugs? they could just be fouled up... I don't really like using those scanners, they don't always work...

But if you just had to replace your FRPS you should check your plugs, and I hope you also changed your oil... When that blows it gets fuel into your oil...

I don't think it's your tune, because this is a recent problem.. your tune doesn't go bad... It could be dirty plugs, dirty MAF, maybe even a vaccuum leak...