AutomagicLS1

iTrader: (18)

At high rpms my fuel pressure is ~56psi and about 60 idling. My car is down some serious power about 75 rwhp. Im in the process of diagnosing the problem which it maybe valvetrain related but i doubt it considering nothing has really changed except different castings and they were both ported. Someone mentioned it could be my stock fuel pump im also running 42lb injectors. If a stock pump was starting to head south wouldnt the fuel pressure drop at wot or is it possible to still show decent pressure but just not have the volume? ALso my a/f on the dyno is showing stupid lean and the a/f will never change. My tune has plenty of fuel in it though.

Lonnies Performance

iTrader: (16)

You cannot maintain pressure without sufficient pump volume.

56-58psi under load is normal as is 58-60 at idle. If your pressure holds stable near max power, you have other issues.