Havent posted in awhile, car is running great on 5psi BUT, if I have under 1/4 tank of gas in the car under hard accel, it will all of a sudden fall on its face and lean way out 16.0-18.0 AFR. With 1/4 tank or more it runs great. Obviously the easy answer is just to keep more gas in it (which I do now) but Im still stumped on why it does this. Has trailblazer injectors with the blazer fuel pump.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Sounds like a definite fuel delivery problem. Check out fuel pressure, and go from there?
My friend recently developed the same problem in her alero, so same motor and everything minus boost. Apparently it has something to do with the baffles in the tank, that is what I was told I never looked into it, but they keep it above 1/4 tank or so and it doesn't do it anymore. they thought it was a plugged cat by the way it fell on its face at first..
It's because of the Blazer fuel pump. It doesn't sit low enough in the tank to get all the fuel. So you're actually out of gas at around 1/4. This has been a known issue ever since the guys started swapping the Blazer pumps in. I believe they found out that the W-body pump (Racetronix?) fits in the J-body tank and works like stock. I don't have any specific threads to direct you to, but I know it's been posted around here quite a bit. Boost forum would be the most likely place for guys to be discussing fuel issues probably though.
i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick
SHOoff hit the nail on the head.....I'm running the f body racetronix pump and harness for almost 2 years no issues with supercharger. Now I'm n/a going turbo and will continue using the racetronix. I've brought the gas light on and still have had no stumble under hard accel.
Thank you for all the info.
3400 SWAP DONE. 187WHP 212TQ (14.2 @100MPH NA) 240WHP 310TQ (N2O)
Nitrous Nate wrote:Thank you for all the info.
Great info! Thanks for sharing.
--------------------------
NCR-SCCA
