went on the dyno yesterday for some re-tuning. boost was set @ 26psi. as soon as the car hit full boost, fuel pressure would hit 65 psi and then drop off to about 56-58 psi. it just wouldn't hold at 65 psi. can this be a bad fuel pump??

 

What fuel pump? Could just be lacking the flow capability at 91psi system pressure.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hpfsi &raquo;</TD></TR><TR><TD CLASS="quote">What fuel pump? Could just be lacking the flow capability at 91psi system pressure.</TD></TR></TABLE>

holley 255 lph pump. toal fuel pressure is 65 psi @ 26 psi of boost. not 91 psi

 

How is your fuel pressure? Does it fall off at higher RPM?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b00stedbyFastrax &raquo;</TD></TR><TR><TD CLASS="quote">

holley 255 lph pump. toal fuel pressure is 65 psi @ 26 psi of boost. not 91 psi</TD></TR></TABLE>

gotcha... how much power are you making? many miles on the pump?