FPR question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Muzzy · 05-29-2003, 10:30 AM

i know this is gettin stupid but jus one quick question...

ok...my fuel pressure is 60psi before the fuel rail...
my fuel pressure after the FPR is 60psi...isnt that wrong????

shouldnt it be 43.5psi after the FPR???

also look at my previous crap so u know my problem..maybe u missed it and u may have some valueable input..cuz i need some help!!!
here-->http://www.zilvia.net/f/showthread.p...hlight=43.5psi

Yoshi · 05-29-2003, 05:10 PM

okay, that thread gave me a headache.
what kind of FPR do you have? You don't see a difference in pressure whether u have the valve wide open or all the way screwed down?

Muzzy · 05-29-2003, 09:41 PM

the reason it gave u a headache is cuz thats 2 threads...it was modded

anyway i have the box stock OE FPR so i cant change it..there is no screw

kandyflip445 · 05-30-2003, 01:01 AM

OMFG THAT WAS SOOOOOOO FUNNY!!!!! I just spent like over an hour trying to help this guy. The reason he was getting 60psi before and after the FPR is because he was pulling the fuel line off and connecting it directly to the guage!!!!!

Ok. I told him how to test the pressure(hopefully you do it right, Muzzy...

). And now for the tests I promised him.

Disconnect the fuel return line at the tank. Use some hose to route the returning fuel to a gas container. Start the engine and look at the pressure reading at the engine. If the fuel pressure is now within spec. check for an obstruction in the in-tank return plumbing. The fuel reservoir check valve or aspirator jet might be clogged.

If the fuel pressure still reads high with the return line disconnected from the tank, look at the volume of fuel flowing through the line. Little or no fuel might mean a plugged return line. Shut off the engine and connect some hose directly to the FPR return port to bypass the return hose. Restart the engine and check the pressure reading again. If bypassing the return line brings the readings back to spec. a plugged return line is probably what you have.

If your pressure is STILL high, apply a vacuum to the FPR to see if it makes a difference in the pressure. It should. If there is no change, replace the FPR. If applying vacuum directly to the FPR lowers fuel pressure, the vacuum hose that controls the operation of the FPR might be plugged, leaking, or misrouted.

I hope this helps you.

05-29-2003, 10:30 AM	#1
Muzzy Zilvia FREAK! Join Date: Jan 2003 Location: TX Posts: 1,555 Trader Rating: (0) Feedback Score: 0 reviews	FPR question i know this is gettin stupid but jus one quick question... ok...my fuel pressure is 60psi before the fuel rail... my fuel pressure after the FPR is 60psi...isnt that wrong???? shouldnt it be 43.5psi after the FPR??? also look at my previous crap so u know my problem..maybe u missed it and u may have some valueable input..cuz i need some help!!! here-->http://www.zilvia.net/f/showthread.p...hlight=43.5psi __________________ lemme have a dollar

05-29-2003, 05:10 PM	#2
Yoshi Post Whore! Join Date: Jul 2001 Location: Washington Age: 48 Posts: 3,003 Trader Rating: (1) Rides Gallery: Yoshi Feedback Score: 1 reviews	okay, that thread gave me a headache. what kind of FPR do you have? You don't see a difference in pressure whether u have the valve wide open or all the way screwed down? __________________ www.360realms.com/S13-S15

05-29-2003, 09:41 PM	#3
Muzzy Zilvia FREAK! Join Date: Jan 2003 Location: TX Posts: 1,555 Trader Rating: (0) Feedback Score: 0 reviews	the reason it gave u a headache is cuz thats 2 threads...it was modded anyway i have the box stock OE FPR so i cant change it..there is no screw __________________ lemme have a dollar

05-30-2003, 01:01 AM	#4
kandyflip445 Post Whore! Join Date: Sep 2002 Location: Arden, NC Age: 40 Posts: 4,460 Trader Rating: (1) Rides Gallery: kandyflip445 Feedback Score: 1 reviews	OMFG THAT WAS SOOOOOOO FUNNY!!!!! I just spent like over an hour trying to help this guy. The reason he was getting 60psi before and after the FPR is because he was pulling the fuel line off and connecting it directly to the guage!!!!! Ok. I told him how to test the pressure(hopefully you do it right, Muzzy... ). And now for the tests I promised him. Disconnect the fuel return line at the tank. Use some hose to route the returning fuel to a gas container. Start the engine and look at the pressure reading at the engine. If the fuel pressure is now within spec. check for an obstruction in the in-tank return plumbing. The fuel reservoir check valve or aspirator jet might be clogged. If the fuel pressure still reads high with the return line disconnected from the tank, look at the volume of fuel flowing through the line. Little or no fuel might mean a plugged return line. Shut off the engine and connect some hose directly to the FPR return port to bypass the return hose. Restart the engine and check the pressure reading again. If bypassing the return line brings the readings back to spec. a plugged return line is probably what you have. If your pressure is STILL high, apply a vacuum to the FPR to see if it makes a difference in the pressure. It should. If there is no change, replace the FPR. If applying vacuum directly to the FPR lowers fuel pressure, the vacuum hose that controls the operation of the FPR might be plugged, leaking, or misrouted. I hope this helps you. __________________ My 240 vBgarage