Part throttle lean AFR's
 

Hi,

I am running with a weird problem at the moment as below:

Running ID1000cc, AMS fuel line Kit, AMS FPR Kit, Aeromotive 340L. Now I have set the base pressure to 43.5 psi with vacc line off, the car starts, Idle and runs fine but only one issue is the sudden leaning out at around 2000 till 3000 RPM !! The AFR will run fine till I get around those PRM and it will lean out till 17~18 AFR, and then as I pass that area it returns to normal AFR !

Now to troubleshoot the problem I put back the OEM parts back one at a time; Injectors, Fuel pump and finally the FPR , and amazingly it ran perfect with no hesitation or lean AFR after changing the FPR !

Put the AMS FPR kit back and same issue ! Its a brand new kit ! Any Ideas ?

Regards,