Long cranking times. Fuel pump primes but not get power when cranking.

[GIZZ]

I've spent hours reading all the posts. I see people post in threads with my same symptoms but no solution. Fuel pump will prime but not get power when cranking.

I have to crank the car over until the oil pressure back up powers the pump. I changed the fuel pump relay, no difference. The fuel pump will prime and I get pressure in the rail the first time I turn the key, subsequent key cycles will not prime unless I wait for maybe 20 seconds. When cranking the pump does not get power/zero fuel pressure until the oil pressure backup kicks in. Once I get oil pressure it fires right up, I can shut it off and it will crank and fire easily. Until I let it sit and lose oil pressure.

I know the cam sensor is working, runs poorly and engine light comes on if I unplug it while engine is running. I was going to check the cam sensor and timing next, would this cause my problem?

Or bad ecm?

 

[salvageV6]

Your car seems to be hard starting for some reason, that is normal operation for the ECM and fuel pump circuit.
Should take 10-15 seconds for the ECM to reset the prime. Car should start on the first prime unless the fuel rail is draining off the pressure via a bad check valve in the pump etc.
Just my .02.

 

[TexasT]

Not sure if the op understands this isn't a "new" vehicle that you "bump" the keep and it busts off. Or if there really is a problem as the ecm generally needs a revolution or two to get it's crank signal established then looks for the other signals.

 

[TireFryer]

^^^

 

[GIZZ]

update,

I put a half tank of gas in it and the long crank issue is gone. Works fine everytime now, no idea why.

 

[John Larkin]

The turbo gods are keeping you on your toes.