how to check fpr

[gar70614]

im having some trouble with my 3500 swap. its a 99 3400 fuel rail, injectors, and fpr. the car runs rough and hesitates on acceleration. my question is, is there a way to check my fpr further. i have tryed to pull the vacume line off at idle and nothing changes. should i use a pressure gauge? and if i need to replace it would it benificial to use a 2000+ fpr?

[Weatheralls Auto]

To check properly you need a gauge.
If it needs replacing I would recommend an adjustable, just be sure to adjust with a gauge.

[gar70614]

should i have steady pressure or fluxuating i dont have the manual infront of me any one know wat psi should be? i know 2000+ is like 55psi but dont remember for 99-

[asylummotorsports]

'99 should be 43.5 pounds

[Weatheralls Auto]

99 GA

With the ignition switch ON and the fuel pump running, the fuel pressure indicated by the fuel pressure gage should be 284-325 kPa (41-47 psi). This pressure is controlled by the amount of pressure the spring inside the fuel pressure regulator can provide.

You may want to adjust higher since you have swapped in a 3500.

I am not sure what if any tune you have.


As a side note, Adjustable FPR is USELESS if you do not have a gauge.

Had a 2000 Cavalier in the other day ( I know I know, not a 60* lol but story fits)
Has a Supercharger, and has an AFPR. <----- No Gauge and never set up with a gauge.

He suspects he rich, so keeps "messing with screw"

I convinced him to install a perm gauge on rail.

After install, I check Fuel Pressure, 19 PSI Normally should be 50 - 55 but with blower even more!

He has been driving like this for 2 years. Very lucky he did not grenade his poor old LD9 2.4!

[gar70614]

lol ld9. thats wat my 99z24 had b4 i BLEW the #1 connecting rod into six parts. now i have the 3500 and a 282 in the z and forget about how much of a pita the 2.4 was. but should the pressure change through out the rpms? ill prob swap to a 2000+ fpr either way.

[pocket-rocket]

Yes, pressure changes with RPMs because the FPR uses engine vacuum to adjust the pressure.