Need some help bigtime please!!

[supeg]

Hey guys. Need some help fast.


Got my truck dynoed last week and my af went up to 13.5 Thought something was possibly wrong with the RWTD tune so I got ahold of James and everything on the tune is fine.

Dyno still running really lean, so I bought a SCT from the dyno guy and getting a custom dyno tune. Well whatever he does he cannot get the short term fuel trims correct at the upper rpms. He tried adding up to 30% fuel and it still leans up at upper rpms.

Anyone know what can be causing this?

Please help

 

[Nvr_Spds]

What are your mods? Do you still have the small MAF?

 

[8urzo6]

What is the fuel pressure?? Are the fuel pump relays working??

 

[supeg]

Mods:

1999 Lightning
6 lower
Ported Blower
C and L Plenum
C and L Elbow
Air raid Intake
90 mass air


Tuner said fuel pressure is good, not sure what the other thi8ng you said is, he is going to check fuel flow tommorow

 

[8urzo6]

my guess is pump or relay. The relay is like a switch that gets power to the pump.