I am pretty much stumped by this recent issue at the track. Regardless of boost pressure or gear my car runs lean above 7300 RPM at the track when it did not on the dyno previously.









I am using
ID1000cc Injectors
DW300LPH Pump
Fuelab Regulator @ 50 Base Pressure
SUNOCO 110 OCTANE over 1/2 tank fuel
Stock lines to the bay, 6an from the hardline through a fuel lab filter to a GE rail.

The fuel pump is rewired and I have verified that the pump receives 14V at 80PSI with engine running.

My first thought was that the pump was unable to supply enough fuel but I noticed the engine running lean at lower boost pressures as well.

Another odd finding was that when increasing fuel pressure at idle caused the engine to idle lean, 70PSI made the idle AFR increase from 14.5:1 to 16.5:1