ChaRgeC230

2006 e350 ran fine all morning. but in the late afternoon, after i got out of the store it started up and i pressed on the gas and car stumbles hesitates and died. Engine would crank over but would not catch.
Checked fuel pump fuse which was good.
Checked fuel pump relay also good.
I opened up the fuel line near the fuel rail and it doesnt have any fuel pressure when i put the ignition on acc.
Could the CPS cause the fuel pump to not turn on? Or do you guys think its the fuel pump?

E500 AMG Sport

I don't know about the fuel pressure part, but if the car restarted after it cooled off a bit you can bet it's the crankshaft position sensor.

DC2021

Did you check the pressure with a gauge or just pushed it? I thought I had no pressure with a push test. But when I hooked up a gauge, I got a reading.

Have you checked for spark?

Its my understanding that a crank sensor will kill both if its failed.

It seems that the symptoms for a faulty CPS are pretty cut and dry. Heat causes the sensor to expand cutting connection. When it cools, its back on line. A progressive problem that will lead to total failure of the sensor.

If you have not had those specific symptoms a CPS is probably wishful thinking. If you can afford to throw a little money at it and are handy, its worth a shot replacing the CPS just for process of elimination. Because it is a common failure item.

I would suggest pulling the back seats, and visually inspect the top of the units that sit in the tank for leaks first though. Its easy. Its free. And its also a high failure item that would explain why you have power on one end but no fuel on the other.

I feel your pain. Good luck

ChaRgeC230

I just took apart the fuel line and tried to prime the fuel but no fuel came out. I tried starting the car this morning but it still didnt start.
Im hoping its the CPS if not i dont know what would cause the fuel pump to cut off unless its bad.
I took a look at the fuel pump there was no leak.