What exactly is the stock fuel pump pressure?

 

I THINK it's 40psi, I could be wrong

 

fuel presure is 49.8 to 71.1 psi

 

Now I know he's confused!

This is the dead head pressure if you were to connect a gage right to the outlet of the pump. This pressure is indicative of whether or not you have a good working pump. That's all these pressures are good for.

What really matters is the fuel rail pressure. This pressure is maintained by the fuel pressure regulator (FPR). The FPR maintains a constant differential pressure between the manifold pressure and the fuel rail pressure. This ensures the injectors are always seeing the same differential and inject a consistant amount of fuel for a given injector pulse. When the FPR is connected and seeing normal idle vacuum levels, the rail pressure should be about 28.44 psi. If the FPR pressure sensing line is open to atmosphere, it will be about 37 psi.

HTH,

Scott

 

If I am not mistaken the 49.8 - 71.1 is the pressure the fuel pump is rated at. I checked that when going with one that had a 95 psi shut off. Rex4Life is right 28.?? at the rail.

 

Ya know that 28 psi is right out of the FSM. Weird that I've never seen that pressure, it was always around 37 psi. I've got a T2 setup but I believe the SE is the same, the FSM write-ups have the same numbers for the rail pressure checkout.

I'm pretty sure the regulator will maintain about 37 psi over what pressure it senses.

If you have a turbo and start boosting, the pressure should go up in equal proportion to the boost pressure.

I'll look into this some more later, maybe one of the other guys will come up with something in the meantime.

Scott