Fuel pressure leaks down overnight

[SJSnelling]

2005 GMC Silverado, 5.3 liter. Long cranking after sitting overnight. Fuel pressure during non-start 0-10 psi. Changed fuel pump (twice). Pressure regulator in in-tank pump. Once started, fuel pressure is 55 psi. After shutting the ignition off, fuel pressure drops to 48 psi, and holds for hours.

 

Any guidance to where to check would be greatly appreciated.

[sefiroxx]

Long leak down is normal, crank on my 01 is common for last few years (as well as on 3 of my 5 gm vehicles).

I have taken to turning the key on, wait 2 seconds, then start.

[davester]

Don't know why your FP would be so low when engine won't start, short of the fuel pump not getting 12V or the pump being plugged.

 

I would first check the wiring connection to the fuel pump and check that it's clean and making a good connection.

 

For my truck, I never wait, just jam it in and turn, and the vast majority of the time it starts.  Evey once in awhile, it'll surprise me and not start immediately, and I'll need to crank it again for another 1/2 second.

[SJSnelling]

Thanks for the leads...turned out to be the crank sensor. Wasn't throwing a code since the first pulse provided fuel, then none...