Ive read so many posts i dont know which way to turn lol..WHATS the best way to get a little more fuel pressure.Im running within reason on gas still drops to 43psi wideopen but my afr is still good 11.3 11.5!!but now with E85 it drops to 30 at 5000 rpm..Probally go back to 93 octane..IS there anything that would help that out sum like a diff fpcm that could spike the pump sum more..

 

I'm losing pressure at WOT so flex fuel pump is not the ultimate solution.

 

Why are you yelling?

 

Can you run a boost a pump with flex fuel pump?

 

(I think he's pissed.)

 

As long as you are running a Returnless fuel system you are going to loose pressure at WO. Just a FYI for you guys.

 

NOT YELLING!!thanks guys

 

Yessir, have a Kenne Bell BAP on my stock FF pump and it's keeping up with my 75# injectors on E85 to about 6300rpm (IIRC). I have a return-style though.

To the OP, shop around for a voltage booster (Kenne Bell Boost-a-Pump or Magnavolt).

Edit: just to clarify, I'm not running out of fuel pump at 6300, that's just where my shift point is

 

Thanks alot i appreciate the help...

 

I tried to do the flex fuel pump for my 2001 Tahoe lm7 5.3 just updating to tell you all the things I ran into. I had to order a flex fuel pump for a 2002 Tahoe. im talking gm factory pumps btw. opening the packing the difference is appearant. the flex fuel pump is physically larger than the stock one listed for my truck. the connectors are different too. mine was a 4 pin flat connector and the flex fuel pump is a 2 over 2 under connector. and the old style connector for non flex fuel pump trucks is different. beyond that the locating tab is the same position the fuel sending unit is of different design and float arm too. looked like it could work. I looked up and cross referenced the wiring for both returnless fuel system trucks. and it will work. I didn't end up doing this.because it was more headache than I wanted but if you get the gm repair harness for flex fuel trucks I think it would work. my new factory pump seems to keep up with my wet sniper nitrious kit 140 shot. I have a 4x2 Tahoe with badlandz coutout motors and its does fine for me hope it helps guys