Hey guys. Decided to upgrade my fuel pump for e85. Was running a walbro 255 on stock wiring and working fpcm. Was feeding 250rwkw with AFR in the low 11's top end no problems.
I upgraded to dw340 lph e85 pump. Installed in same configuration as walbro and went for test drive. Ran well but was leaning out, top end AFR of 13+ was occurring. Was thinking this pump requires more voltage.
I went back home and rewired the pump with a 30 amp relay and wiring to the battery. Went for test drive again and ran well cruising around but extremely rich when on boost, I saw AFR of low 9's. Ran like shit, WTF.
Not sure what's going on.
I was assuming that my stock fpr would cope. Is it not able to?
Is it because I had the car tuned with the fpcm and now running without?
Maybe the walbro was weak and the car was tuned on low fuel pressure?
Any ideas and advice or explanation of what's occuring appreciated.