LB7: Help?!?!?

[NTXDURAMAX]

I got a 2003 lb7 with 40 horse injectors, intake, exhaust and efi live! I'm noticing a little cut back or backing off when I'm going 80+. I'm pretty sure I need a fuel pump or lift pump of some sort n I was trying to get some input on what you guys would do!

All advice is much appreciated!

 

[Kspen90]

You need to log desired and actual rail pressure to see if your cp3 is keeping up with desired rail pressure then go from there.

 

[Kspen90]

Also do you have a race valve or a fprv shim kit? How long have you been running your current tune and when did your problem start?

 

[blk smoke lb7]

Have you swaped the fuel filter and tried it again?

 

[Kspen90]

Have you swaped the fuel filter and tried it again?

X2.....i always seem to forget the simple things

 

[Dirtymaxx03]

you have 40hp sticks and no lift pump? there's your problem