So I hooked up a fuel pressure gauge to the schraeder valve on the fuel rail at SZ while at the dyno day just to see what was happening to my fuel delivery which would cause me to be running lean. I never did 13:1 afr on the dyno, (It did jump from 11:1 to 12:1 between the 2nd and 3rd pull) but what did surprise me was my fuel pressure readings. At idle my fuel pressure was 59 psi. And whats even more interesting, is at WOT the fuel pressure stayed right at 59 psi the whole time and didnt rise. Does walbro make a low and high impedance fuel pump and im running the high instead of low? Something isnt right. Im thinking my pump was getting hot and causing my afr to go from 12:1 to 13:1 from the 2nd to 3rd pull.
Btw, heres a picture of my dyno graph and afr.
