Hard Start On 1st Try

Eddie 70 · July 9, 2010

My truck for some reason will not start on the first try. If you hit the key the truck will run through its 5 seconds of trying to start itself until it times out. The next time I try to start the truck, it cranks right up beautifully just like it should and it runs as smooth as glass. I checked for codes this evening when I got home and there are none showing using a CEN-TECH Scan Tool. I scanned it a few times and nothing showed. I have not pulled any plugs on the truck yet as I just got it last Tuesday evening and have not had a chance just yet.

Anyone have any ideas as to what may be causing the hard start symptoms on the first try? All help is greatly appreciated.

Eddie 70 · July 9, 2010

I guess I should add, it is an 07 GMC Sierra ECSB 5.3 AFM and is flex fuel capable.

mrkleen · July 9, 2010

check the fuel pressure regulator

txab · July 9, 2010

Check fuel pressure. Both running and stopped

Eddie 70 · July 9, 2010

Will check both of those this weekend and report back.

Eddie 70 · July 11, 2010

Just came back up from testing the truck. With the gauge connected to the fuel rail and turning the key on, the pressure comes up to about 10 PSI and then dropped right back down to zero. Starting the truck and the truck will crank for the 5 seconds and not start, all the while the pressure is building. Hitting the key immediately after and the truck will start and the pressure will build to approximately 40 PSI and the truck runs perfect.

Pressure regulator or fuel pump or injectors?

txab · July 11, 2010

Pressure specs are 55-62. It should hold pressure after you turn the key off. If it drops more than 5 lbs in a minute then there is a problem, according to the manual. Pressure reg is integrated in the fuel pump. Sounds like it's time for a replacement

Eddie 70 · July 11, 2010

When I turn the truck off after running, the pressure will drop right back to zero.

What happens to the pump next? Will it hold out for a week or should it be replace tomorrow?

Eddie 70 · July 11, 2010

gmpartsdirect.com has fuel pumps listed for up to $245.95. Anyone use them and how fast is their shipping? Would the pump be available for me to use next weekend. My local NAPA has the pump but the price is $404-494 depending.