Hard Starting

[the hammer]

Hey all,

 

Truck is hard starting only after sitting for a while, like overnite. After initial startup there is no problems of idle or running or re-starting the engine. Battery, starter, and alternator are good. 90k on the odometer. is this most likely a fuel pressure problem? Thoughts?

[tanked_darren]

I must ask: how do you know the battery is good.

[the hammer]

I have superpowers.

[the hammer]

And I had the gents at pep boys test it.

[RyanbabZ71]

Sounds like it could be the fpr (fuel pressure regulator). My 00 had an issue like yours only when cold. Pop it off and check it out

[txab]

Sounds like it could be the fpr (fuel pressure regulator). My 00 had an issue like yours only when cold. Pop it off and check it out

2006 FPR is part of the fuel pump assembly in the tank. Check your fuel pressure reading. Key on, engine off.

[the hammer]

i wondered where that regulator was located on my truck I looked for 10 minutes around the engine and couldn't find it, now I know why. Iw ill try and find a place that will let me rent a pressure guage, the advance auto here said they don't rent those so I will check autozone. I will post the PSI when i get it done hopefully by tomorrow.

[the hammer]

Key on, truck off my psi is 52-54 and drops while watching the gauge. I took the readings after i drove the truck to the store to get the gauge, though so the first reading may have been high compared to the one i might get sitting overnight. Engine running it is 60-62 needle shaking ( i assume this is normal shaking with the pump working).

[txab]

55-62 psi is what you're looking for. After pump stops, pressure should stabilize and remain constant. After 1 minute it shouldn't decrease by more than 5 psi according to specs.

[the hammer]

ok took psi this am and it was def 52 with key on engine off and cold engine. The pressure slowly decreases just by standing there and you can watch the needle decrease. So, based on the PSI alone do i need to dig into the gas tank and replace the pressure regulator?

 

What should my next step be?

[RockySierra]

a slow pressure drop-off would be normal after the pump is off I would think. That being said, if you do go into the tank, you might as well replace the entire fuel sending unit while your in there. The fuel pumps on the GMT-800s are known for being very crappy and unreliable. Many a GMT-800 owner on here including myself (on a previous 99 Silverado) had the pump go out between 70,000-130,000 miles.

[the hammer]

Other than what to do next, is my fuel pump and pressure regulator together? Or are the separate but yet both still in the tank?

[the hammer]

Any suggestions?

[Doug_Scott]

I am going to go back to the beginning. When you say "hard starting" what exactly do you mean? To me, hard starting could mean slow cranking, or cranking that just does not have a good rhythm (inconsistant cranking sound of engine).

 

When you had the battery "system" checked, did you just drive in sometime during the day to have it checked? If you did not have them check it after standing overnight, then the test was not in context. Having them test it when you know it will not have a problem starting seems to be a waste to me.

[RockySierra]

In the mornings, if you prime it a few times by turning the key to run and off and run and off (waiting 2-3 seconds between on and off) will it fire right up? That's how I determined the fuel pump was going out on my old 99 Silverado and was very common back then as per the posts on this site.