Fuel Pressure 60-40psi????
10-26-2006, 08:13 PM
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Fuel Pressure 60-40psi???? My fuel pressure droped from a steady 60psi on the dyno to 40psi. It was not a graduale drop it seemed like it dropped quickly to 40 psi and then stayed steady. NOt sure what RPM or how much boost. I can remember the turbo screaming so I was in boost I'm gonna put a new Delco filter in and see If I can figure out what rpm, and or how much boost when it drops. I'm thinking bad pump? or regulator? 
10-26-2006, 09:41 PM
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How long have you been runing your current set up? Mine is similar except for my procharger... My stuff worked perfect for 10,000mi... Now its doing what just happened to you. Im thinking the Fuel pressure regulator is going out or the pump is dying... Im still trying to solve this little mistery of mine. Hope this helps a little. Good luck
10-26-2006, 09:51 PM
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Is that an inline or intank pump? Im having a similar issue. I have a recent post up also about this. Some guys are pointing toward the fuel pump just simply wearing out.
10-26-2006, 10:06 PM
#4
Seems like this has been a hot topic lately...I've noticed a fuel pressure drop under heavy load even with my stock internal car with the stock fuel system (5-6 psi is normal for my car, and happens every time I got WOT). It's just that very few people pay attention to it unless they are tracking a problem (like they just can't make the car rich enough).
10-26-2006, 10:40 PM
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My pump has been in for two months, hope its not worn out. A few psi wouldn't worry me but I was dropping from 60 to 40. Thats huge. It was a quick drop also. Put a new Delco fuel filter in tonight. Taped my test guage to the windshield, and made few 2nd gear runs, I didn't see a drop but its night out and hard to see. Also the dyno sesion was all 4th gear pulls. Hard to do 4th gear pulls on the streets of SoCal 
10-27-2006, 12:32 AM
#6
i drop about 5 psi from idle to wot. i start at 65 then at wot it goes to 60. this is normal.i check it because the of what MeentSS02 said. i kept adding fuel from 6500 to 7500 cause the car stayed lean and it didn't change squat. it kepted going leaner the high it reved. injectors are on the way
Last edited by BLUEBALLS ZZ; 10-27-2006 at 10:15 AM.
10-27-2006, 06:31 AM
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Yep, my car is doing the same thing. Had the tank down last night and everything looks fine. Its a walbro 255 lph and its been in there for 20,000 miles.
I'm thinking that maybe the regulator is bad or the pump is shot.
Is there anything up front that could cause the pressure to drop from time to time?
I'm thinking that maybe the regulator is bad or the pump is shot.
Is there anything up front that could cause the pressure to drop from time to time?
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10-28-2006, 11:19 AM
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Whats the regulator on the rail inlet under the hood? A check valve to keep the injectors pressurized?
I dropped my tank and the hose is fine. Didnt see anything wrong.
I'm just going to replace the pump again.
Does anyone know the walbro model pump for the 99-02's? I had it written down somewhere.
I dropped my tank and the hose is fine. Didnt see anything wrong.
I'm just going to replace the pump again.
Does anyone know the walbro model pump for the 99-02's? I had it written down somewhere.
10-28-2006, 11:24 AM
#10
that inlet doo-hickie you speak of is called a Pulsator-acumulator.It job is to smooth out the injector pusles in the fuel rail so the injector don't hammer themselfs to failure.It has nothing to do with line pressure.Before you replace the pump be sure to test the pres-regulator in the tank carefully.I had trouble with mine dropping pressure.
10-28-2006, 12:40 PM
#13
Might be getting some new injectors myself...my stockers are at 90% already. My fuel pressure drop seems right on the money, even after I just replaced my fuel filter. Starts at 58 psi (idle and cruising), and drops to 52-53 psi at WOT, and comes right back to where it should be after letting out on it.
10-28-2006, 06:10 PM
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I just ran some 4th gear pulls to redline, on the highway @115ish mph and My fuel pressure stayed to 60. Only thing I did was put a new factory filter back on. So unless the Dynapak Dyno can put more load on my car than a redline run in 4th I think It was the Sh*tty AutoZone not made in the USA Filter. Oh yeah and The AC Delco filter was $16 and the Autozone $6. I should have just gone to the dealer in the first place.
10-29-2006, 11:12 AM
#15
I just installed a brand new fuel pump (walboro gss340) and ac delco fuel filter yesterday after my fuel pump started giving out. Although I can tell that the new pump works I still see a drop in pressure. When I'm at about 5-6 psi of boost I'll see my fuel pressure drop to 50-52, but quickly goes right back up to 60 psi while changing gears or during idle. What I experienced when my pump started giving out was that my fuel pressure was at 54-56 psi and the car had a certain hesitation from a start and would also drop to about 40 psi on runs over 6 psi of boost. The pump finally did give out on me and left me stranded on the highway. Now with the new pump the car feels peppier and feels alot better.. I'm still left scratching my head over why I'm still dropping pressure, but I'll find out sooner or later.
11-14-2006, 07:13 AM
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I was chasing a fuel pressure problem for 2weeks. Added a new Walbro fuel pump, drilled my fuel bucket, added a Kenne Bell bap, went to larger fuel line. I finally gave up and took it to a shop. The whole time it was a faulty electronic fuel pressure gauge. Are you checking it with a manual or electric guage?
Good luck.
Good luck.
11-15-2006, 09:48 AM
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I myself have an Autometer fuel pressure gauge (tach style, not digital) and it is very accurate. I made sure of this by taking it to a buddy's shop and seeing if his numbers matched up with mine, and it was 100% on the money. Just make sure you wire it up right.
