is it on shoeboxes website?

 

Fuel pressure regulator?

 

what is the fuel pressure suppose to be?

 

Stock is 43.5 psi.

 

would that be stock fuel pump? what would make it modified?

 

Fuel pump shouldn't make a difference.

 

Fuel pressure setting should match the pressure at which your fuel injectors were flow rated. Or the flow rating of the injectors, set in the PCM must be adjusted to the system operating pressure.

Stock system should hold 43.5psi at idle, with the vacuum compensation line disconnected. GM accepts anything between 41-47psi as meeting spec. Reattach the vacuum line, and the pressure will drop proportional to intake manifold vacuum. A 6-8psi drop below the "no vacuum" pressure is normal for a stock cam. Less pressure reduction for a more aggressive cam.

Take it out on the road. At WOT/max RPM the system should continue to hold at least 40psi.

The stock fuel pressure regulator is capable of controlling the pressure correctly for much larger than stock pumps.

http://shbox.com/1/fp_reg.jpg

 

when you shut the car off how long should the pressure stay ?

 

There should be some pressure even after hours have passed. If not, that does not necessarily mean that the pump won't provide good pressure, but it could mean there is a check ball problem, leaky injectors or line, etc. Retaining pressure allows the car to start better from a cold start, even though it does prime for 2 seconds when you turn the key to ON. There is fuel pressure testing/problem chasing info on my Tech Page.

 

how can i figure out what is leaking i have taken the regulator apart (its an aftermarket one) and nothing seems to be wrong with it. when it runs it builds pressure (im using a pressure guage) and when i turn it off you can actually see the pressure drop to about 10 psi is this normal?

 

Is it an Aeromotive? Mine started doing that a few days before it crapped out completely.

 

i believe it is does it hold the pressure ?

 

Aeromotive fuel pressure regulators to not hold pressure after the pump shuts off. They do that new. I have talked with Aeromotive it is normal.