low fuel pressure?

[eastcoastchaos]

i'm about 90% sure i have a fuel problem so i got a gauge and the adaptor which took me 4 days to find and it's reading 20 psi when i turn ignition to the on position. i've read lots of stuff about high pressure and leaking pressure but what does low mean. is my fuel pump crappen out.my car seems to be running really rich, b/c the plugs get covered in a hurry and the few times it's almost started were w/ the pedal to the floor or the fuse pulled. maybe there is so little pressure that it's just dripping in, not spraying like it should?

and i'm not totally confident on the gauge, i tested my girlfriends car but she has a valve on her fuel rail, i had to only use the top actual gauge part for mine. i can't hook it up w/ the pressure release hose and the valve. would it read differantly with the gauge screwed right into the adaptor. thanks.

[1991S13]

To check the pressure you release the fuel pressure (pull the fuse and let the car run until it dies), and hook the pressure gauge between the fuel tube and fuel filter.

At idle with the fuel pressure regulator valve vacuum hose connected, it should be close to 34psi. With the vacuum hose disconnected, it should be roughly 43psi.

A bad MAF could be causing you to run rich, I'd check that out.

[themadscientist]

If you do have low pressure I would try a new fuel filter before I went after the pump.

[eastcoastchaos]

brand new filter. and MAF? thats new to, and running too rich would mean more pressure or bad coolant sensor or something, but the fuel pressure is mechanically operated and should be 34 psi regardless of the maf.

[1991S13]

I didn't mean the MAF was causing you to have too high or too low fuel pressure, I meant maybe you have a bad MAF and that is causing you to run rich.

[eastcoastchaos]

ooo, well either way it's out of a running car so i'm positive it's at least decent. the ohm test came out good too