Ok here's the issue i have a supercharged 95 z, the fuel pressure is falling off unfer boost. I put in a new regulator, and pump and still it's galling off to 40 lbs under boost. We are supposed to be leaving for the track tomorrow

 

How does you S/C system add the extra fuel? Does it have an FMU? Or are you running an S/C tune on the stock PCM?

How much boost are you running? What size injectors?

Have you changed the fuel filter?

 

stock pcm with a s/c tune, 60 lbs injectors, 15 psi of the boost. And i forgot about the filter but i'll change it after work.

 

Assuming then that the FPR is boost referenced. Have you checked the boost pressure line to the FPR to make sure its not leaking?

 

Yes it is not leaking. I put a new one on it.

 

ttt

 

How big is the pump? Brand?

When you said "Yes it is not leaking. I put a new one on it." did you mean you put a new boost reference line in, in addition to a new FPR?

 

The pump is a walboro 340 and yes i meant the reference line sorry i was at work and rushing

 

ttt

 

ttt

 

Please don't "TTT" more than once in as 24-hour period - see "sticky" at top of forum.

The Walbro 340 is a 255LPH @ 435psi pump. With the kind of BSFC you need to run with a high boost S/C application, it would be good for no more than roughly 760 flywheelHP. With 15# of boost and dual I/C's I would assume you are making at least that kind of HP. Possibly the pump isn't large enough.

Have you considered posting this in the "Forced Induction..." forum?