Fuel pressure dropping????

[fivelitercoupe]

Lately my brothers 94 gt has been dropping fuel pressure when you get on the gas. It idles fine at around 35lbs and then when u get on the gas it drops down to just above 5lbs and it runs like crap obviously, it does this free reving and when you put a load on it. Any ideas on what could be causing this. Odds are its the fuels pump but what do you guys think? Thanks for the help....

 

[HISSIN50]

will a stang even run on 5 lbs? in any case, i would be testing the FPR - if it checks out, sounds like it could be pump time.

good luck.

 

[go-stang5.0]

I had the same problem before you check the pump spend 5 bux on a fuel filter. I got bad gas some time ago and it felt like my car would hit a wall at 4 grand but anything below it would be fine. Turns out my FP was dropping too when I revved it. It was my filter, and after replacing everything was well.

 

[fivelitercoupe]

Thanks go-stang5.0, Sounds exactly like the problem i have and i think i will obviously change the filter first but if that doesnt help, guess i gotta drop the tank. Thanks for the help guys

 

[Stangfreak95]

I have the exact problem as we speak. It does the same thing with my new Accufab AFPR and my stock regulator. When I start the car, the pressure is at around 34psi. After minutes of driving (or a pass at the track) it will be at 24psi ! I first thought it was my fuel filter so I changed it and same problems. My injectors have about 700miles on them so I doubt that they could be "blocked". I'm not having any leak anywhere. I'm 99% it's my fuel pump. When I was trying the nitrous system the other day, it wasnt working because of my fuel pressure safety switch was detecting the low fuel. Thank god or I'm sure I would of heard a Boom coming from the engine

 

[go-stang5.0]

YEa its either the filter or the pump in that situation. Hopefully its just the filter. That is the first thing to try anyways since its a lot easier to do than changing the pump, plus its basic mantinance so its not like your wasting money. I just blipped my throttle from my TB and watched the fuel pressure drop instantly....I did'nt like that one bit. But hey sometimes the easiest solutions are the right ones...and thats why you try them first.