no static fuel pressure!

[rustybullet]

So I checked my fuel pressure the other day as I was having stalling issues in my 318.

Well when I turn off the car the pressure dropped to 0 almost instantly what gives?

I did have 40 psi at idle, 50 with vacuum line off fpr but 0 hold pressure.

[jlevie]

The check valve in the pump has failed or the FPR is leaking. To see if the FPR is at fault. Run the return line from the FPR into a container and jumper the relay or start the engine to get the rail pressurized. When the jumper is removed or the engine stopped, flow from the FPR should almost immediately stop.

[rustybullet]

Well it can't be the pump as it is new. If the fuel pressure regulator is bad would that cause the pump to work harder to keep fuel pressure in the rail?

[dnguyen1963]

Some of the newer pumps do not have a check valve built-in. Someone reported that Tre340 pump did not have a check valve so the pressure would drop to zero when power was off.

[jlevie]

Well it can't be the pump as it is new. If the fuel pressure regulator is bad would that cause the pump to work harder to keep fuel pressure in the rail?

A new BMW pump will always have a check valve, an aftermarket replacement may not. If the pump is a new BMW part, retrun it as defective.

Yes, a bad FPR will increase the work required of the pump.