what should fuel pressure readings be?

[briandors]

Can someone with a Haynes or other service book look this up.

 

I want to do a fuel pressure test on my dad's 1989 3.1 Regal.

 

What should all the different pressures (ignition on, cranking, idling, etc) read at the fuel rail???

 

Thanks

Brian

[manitcor]

should be a solid 45psi with only variations and drops of 5-10psi in any given situation

[briandors]

So I should see 0psi when I hook up the gauge (car has been sitting a couple days).

 

45 psi when I turn the key on.

 

45 psi cranking and idling?? Should pressure go up if I rev the throttle?

 

I just bought a gauge and am learning about this process.

[manitcor]

the fuel system should remain pressureized with the car off. However you o let off pressure when hooking up the gauge to the shrader valve.

 

When you turn the key on the system is primed to 45psi by turing the pump on for 2 seconds.

 

When cranking and running the pump is on constantly. The Fuel Pressure Regulator maintains the 45psi. You wont see pressure go above 45psi however at WOT and other load situations youll see it drop between 5 and 10psi.

 

To obtain a pressure above 45psi you need to change the regulator.