10 psi

[jjubeck619]

Newbie here........

I have a 99 gt thats having problems runing. I was thanking it was a fuel problem so i checked pressure at the fuel rail and got 10 psi with the pump on.....that cant be right can it? Anyone know what the pressures should be and where the hell the fuel filter is?

Thank you!

[edbrycem]

the filter shoud be under the drivers door area. if the key is turned on but not running, 10 psi sounds about right. if you "cycle" the ignition (off, on, off, on) a couple times it should rise considerably. I dont know the exact specs on it though, i'm thinkin around 40ish psi

[BNaylor]

See link below for location and replacement procedure for fuel filter:

http://www.pfyc.com/supportfiles/gasfilter/

Fuel pressure should be 48 - 55 psi in the fuel pump prime position - ignition to run/on not start. While running at idle it will be in the same range with vacuum disconnected off the fuel pressure regulator (FPR). With vacuum connected at the FPR it will drop but I have never seen it go below 45 psi.

[jjubeck619]

so your saying it should be atleast 40 psi just with the key on?

[jjubeck619]

oh yeah and thank you very much for the link and your help!!

[BNaylor]

Originally Posted by jjubeck619

so your saying it should be atleast 40 psi just with the key on?

No it should be a lot higher. 40 is too low and out of specifications for proper fuel pressure on your year, engine size, and model Grand Prix. With key on which is fuel pump prime it will be in the high 40s. On most GTs I see at least 48 psi. 52 psi is typical. 48 - 55 psi is a GM specification that is very accurate.

[mimi46b]

hello i do not know about cars but can you answer my question for me.

[BNaylor]

Originally Posted by mimi46b

hello i do not know about cars but can you answer my question for me.

What is the question?

[richtazz]

10 psi means your fuel pump is shot most likely. I've never seen a fuel filter clog so bad it reduces pressure that low. A bad FPR (fuel pressure regulator) will cause a fuel pressure drop, but not that severe. Bob is correct (of course) on the fuel pressure spec.

[mimi46b]

Originally Posted by bnaylor

What is the question?

Last night, my key got stuck and would not come out now this morning it came out but keeps cutting off it will not stay started.

[BNaylor]

Originally Posted by mimi46b

Last night, my key got stuck and would not come out now this morning it came out but keeps cutting off it will not stay started.

What engine do you have and what model Grand Prix to include mileage. Info is helpful so others can weigh in to help you.

BTW - You might consider posting your problem in a whole new post instead of working off this one so you get better visibility.

[jjubeck619]

Thank you for the replies it really helps to have other knowledge and opinions on this...

I can hear the fuel pump priming or atleast coming on, and before turning the key to the on position it only reads 4-5 psi, and with the pump priming it rises to about 10 psi. is it possable that the impellar on the pump came off?