[John Z Williams]

I just wanted to say you might want to check your fuel pressure under boost and at least a/f under boost if you are running a tuned car with more boost.

This is the second time I went to put a brand new fuel pump in a car and have it fail and not have good fuel pressure. I end up having to change the pump twice. On my 9k aero stage 3ish and 23psi of boost my stock fuel pump was giving me an a/f of a steady 14.3/1 under WOT and I suspected the fuel pump.

Replace it: Goes to 17.5-18.5 a/f on wot in third gear, maybe 15psi of boost.

Replace it with yet another pump and this time, 11.5/1 and some 10.9/1 with second replacement pump...

Whats up with these insert fuel pumps? Twice I had this happen on two different cars... That sux...

John

 

[Norman Lovie]

Thanks John, ive got an intermitant issue with my mid range performance which I was thinking - fuel pump, now you,ve convinced me. But could it be the check valve & a bit of crude playing up with you, I tested mine off the car using a compressor

 

[John Z Williams]

Well since I have had 4 bad fuel pumps in 3 years, I plan to check every single one of them with at least a wide-band which will tell the story if the fuel pressure is bad.

I recommend having it checked immediately. If I had not checked my Aero, I would have surely burned my motor down!

John