I am running a Walbro 255, Corvette filter, and -6 line to the fuel rail. On hard acceleration fuel pressure will drop to 45. Has anyone had that problem? How about a restricter or poppit valvie on the return line? Any other ideas?

 

Can I suggest another area to cover. Electrical... what is the voltage to the pump as you accelerate ?.. as the Engine may require more voltage/amps to keep up with the increase load of the engines electrical system.. the Fuel pump electrical source may be dropping and suffering.. ?

Just another area to check, I am running the Racetronix heavy wiring harneless, fuse and relay that connects to the alternator.. and as the increase in engine rpm go up, so does the voltage/amp of the alternator which increases the voltage and amp to the fuel pump. Racetronix used to have a good write up on this subject.

What gauge is the 12+ source to the pump or relay?
Where are you getting your 12+ source..?
Do you have a good ground ?

 

is your tank baffled ?

 

The wire is what was provided in the Speartech harness. No baffel but it will do it with a full tank.

 

Does battery charge state, have anything to do with not getting enough voltage to the factory in-tank fuel pump?

 

Is that wire in the Painless harness the relay enable wire or the power to the pump/relay 12+v wire ? what gauge wire is it..?

there should be two wire that are key for the pump relay.. one will activate the relay which size is not that important. But the 12+v wire to the relay is the key one. where is it connected to ?, Battery, some junction box, alternator ?.. and what gauge wire is it..