Running lean under boost

shadow85

Would like to know if anyone else with a boosted Z has experienced the car running lean under boost, and what their issue was and how they fixed it please?

Only just had my TT build finished up and currently being remote tuned by Seb, but ran into this problem of the car going lean when I tried the WOT pulls.

AAM Competition RHD TT Kit
ID1050x
Walbro 460
CJM S1.E System
Fuel Pump Relay Kit
Running e85


Below is part of am Ecutek log when I tried the pull:


My workshop has looked for possible fuel leaks and pump voltage and that seems to be all ok. So they assumed my Aero340 pump before was too small, so they changed the Aero340 to a Walbro 460 and that instantly made the car feel better and more responsive but the lean issue was still there although not as bad as before the new pump.

Seb has tried to force more fuel in the tune which also helped but as you can see from the graph it still progressivly gets more lean under the load as it increases.

My fuel pressure on idle is @42 psi, I think that is with the vaccum/boost hose connected, not sure if it should be higher?

Atm I am waiting till Monday to get it onto a dyno so we can check the fuel pressure under load, as suggested by Seb.

Has anyone had this problem before please share you experience with me, thank you!