whats up with my fuel psi

[sweeda]

My 04. 5 with a fass pump model #1001. When first installed in Jan. 07 the pressure at the pump port was 14. 5 NOW in 17. 5 to 18 psi changed the filter cleaned the seperator and its still that high. AND at the same time the CR presure has dropped slightly 1000 to 2000 at different rpms the most troubling though is when hot the idle psi is as low as 3000. norm has been 5000 hot and 8000 cold sorry abit long but are these the signs of bad things to happen or is this just due to the summer fuel in California. smoke out the pipe seems down and so is power. IT takes more pedal to raise the egt, but still goes. what do you think! any ideas! Thanks!

 

[steved]

The low rail pressure sounds like a failing FCA...



The FASS pressure might just be coincidence... mine varies from 10 to 18 psi.

 

[NRussell]

My Fass HPFP 95 always ran around 15-17 PSI and went to 20 PSI for a couple of days this week and is now pegged at 30 PSI on my Danin Fuel pressure gauge. I also am wondering what is wrong.

 

[steved]

Don't always assume the pump is at fault... might be the guage or the sending unit.

I run a mechanical guage on the line, behind a snubber. Elevation changes will affect PSI... I had less than 9psi on this trip to WA coming through the higher elevatins.

 

[sweeda]

good calls! let me bounce this off you failing FCA would this increase the fuel to the return line and the FASS is just keeping up the flow and how can I check a sending unit without replacement first. gauge is newer than the pump.

 

[steved]

good calls! let me bounce this off you failing FCA would this increase the fuel to the return line and the FASS is just keeping up the flow and how can I check a sending unit without replacement first. gauge is newer than the pump.

I don't think so... FCA limits fuel flow...



And unless you have a guage to compare the sensor with, no.