Hey all. I'm getting my fuel system ready for turbo, so I decided I would hook up my new electric fuel pressure gauge, just to get some base fuel readings. So I unscrew the schraeder valve, attach my gauge sender, start up the engine, and what do I get???? 40psi, +/- 1psi. Now from what I understand it's supposed to be around 55psi, is this true??? or is 40psi normal??. I don't wanna continue on my new fuel pressure regulator and new pump until I know that my car is alright. Is my old fuel pump tired???, old regulator gone bad???, plugged line somewhere??, or is everything alright??? It's always run perfect and still does, just concerned about the numbers. I know that I'm replacing all that stuff anyways, I'm just a little leary of continuing until I get the go ahead. Thanks in advance.

John

40 psi would be fine for a 1995 car at idle. They have a vacuum referenced fuel pressure regulator, so its 40 psi at full vacuum and 50 psi at 0 psig manifold pressure. The later cars have a fixed fuel pressure. I believe its fixed around 50 psi and the ECU compensates for varying intake manifold vacuum. Looks like you have a '97+, so it seems a little low. I wonder if a clogged fuel filter could have this effect? I'm not too familiar with the later cars as I have a '95.

Corbin

'95 ESI-T
HRC+FMIC+ETC...



Gimme fuel...Gimme fire...Gimme that which I desire

Originally posted by Corbin
40 psi would be fine for a 1995 car at idle. They have a vacuum referenced fuel pressure regulator, so its 40 psi at full vacuum and 50 psi at 0 psig manifold pressure. The later cars have a fixed fuel pressure. I believe its fixed around 50 psi and the ECU compensates for varying intake manifold vacuum. Looks like you have a '97+, so it seems a little low. I wonder if a clogged fuel filter could have this effect? I'm not too familiar with the later cars as I have a '95. Corbin '95 ESI-T HRC+FMIC+ETC... Gimme fuel...Gimme fire...Gimme that which I desire

Hmmm, that's something I didn't think of. I'll go and pick one up today and try that. It does stay exactly the the same. Right at 40psi, at idle, and at static(WOT). Mine is a 98 so it is the different fuel system. Any other ideas. Thanks again

John

I think your numbers are fine. I assume your getting readings from just the stock in-tank and stock filter - which it probably a little dirty by now. When you go turbo and hook up your secondary fuel pump it will push a little harder which will probably put your numbers right where you want them. If your FP was off you would know it.

Originally posted by techboy
I think your numbers are fine. I assume your getting readings from just the stock in-tank and stock filter - which it probably a little dirty by now. When you go turbo and hook up your secondary fuel pump it will push a little harder which will probably put your numbers right where you want them. If your FP was off you would know it.

That's kinda what I was hoping, thanks for the info. I found out that when my car does go into closed loop it goes up to about 45-47psi. And yes, stock fuel pump and stock filter. Now time to decide what fuel pump I want and get a new filter. What does everyone like for fuel pumps???? Time to go hit the search. Thanks everyone.

There is only one way to test the FP on a 96+ and that is with the engien off and fuel pump energized. the rest is irrelevant so to speak. each car is different idling. For example

My 97 With 3/8 lines SFMU is set at 47PSI static with engien off and idles at 47psi.

My 96 Static with engine off (255 walbro) is 49~50 PSI and 35psi at idle.

Go figure....just the way it is.

Terry

96 Eagle talon ESI
Star Stage II - Boost/oil/EGT gauges

97 Eclipse
Greddy header/evo exhaust - SFMU/return line - Stage 2 6 puck Sprung hub MIBA clutch - Shortened shifter - Koni Yellows w/eibach prokit - Stillen Fr/Rr swaybars - ceramic intake - DEI Keyless entry alarm - Niche 17" Shoks

Waiting to be installed: Apexi AFC, HKS EVC IV, 450 Turbo injectors, GSX Front brakes (need rotors)

Mitchell on Demand copies available