What is good fuel pressure at?

Also, easiest way to check it?

 

I believe the system pressure with the pump running should be between 41-47 psi. You need a gauge to test your pressure which I believe hooks onto a test valve. Schrader valve...

Check out shoeboxes site... Testing Fuel Pressure

 

The Schrader valve is located on the crossover tube for the fuel rail in the back of the intake manifold.

 

Yep shoebox has a great write-up on that.

 

when you first turn the key, should go to about 45psi or so. When the car is running with the vac hose off, should be about 43.5psi. With the vac hose back on, should drop between 3-9psi or so.

 

Its important to check the pressure with the engine under full load, at max RPM/WOT. Under those conditions, fuel pressure should never drop below 40psi.

Idle, no vacuum line connected, you want to see 43.5psi, but GM specs accept anything from 41-47psi. How much the pressure drops when you reconnect the vacuum line, will depend on the cam and intake manifold vacuum. Stock cam will typically produce a drop in the range of 6-8psi. A larger cam will produce a smaller drop when you reattach the vacuum line.