Hard starting wont hold fuel pressure

dancruiser · October 22, 2012

I'm here because I have a 2001 Chevrolet Silverado 2500HD 6.0 gas 2WD.

For the last several months the truck has been hard starting after sitting for a few minutes. It is also intermittent fuel gauge reading trouble. The gauge fluctuates from full, when full, to empty, it is also very slow to reach full after being filled from close to empty. I changed the fuel filter. I also tested the fuel pressure it does not hold fuel pressure for any time at all. While running it is around 50-52 psi. once turned off the pressure drops to zero. I can hear a click or thunk from the fuel pump when I cycle the key. What is the problem? It runs fine but I do notice a lot of black soot at the tail pipe.

txab · October 22, 2012

Looks like it might be fuel pump time. Fuel pressure reading should be taken with key on, engine off and should be 55-62 lbs. Check the fuel pressure regulator. When you remove the vacuum hose from it, if there is fuel present, then the regulator has failed. If it won't hold pressure after key off, then the check valve in the tank has failed, you have an injector sticking open or a bad fuel pressure reg. Also the fuel gauge problem is part of the pump as well. Are you saying the gauge is slow to show "full" after filling or the tank is slow to fill at the pump?

Have you checked for any codes?

dancruiser · October 22, 2012

Looks like it might be fuel pump time. Fuel pressure reading should be taken with key on, engine off and should be 55-62 lbs. Check the fuel pressure regulator. When you remove the vacuum hose from it, if there is fuel present, then the regulator has failed. If it won't hold pressure after key off, then the check valve in the tank has failed, you have an injector sticking open or a bad fuel pressure reg. Also the fuel gauge problem is part of the pump as well. Are you saying the gauge is slow to show "full" after filling or the tank is slow to fill at the pump?

Have you checked for any codes?

No I have not checked for codes because there is no check engine light on. It is slow to show full. It fills just fine. I have checked the FPR and it seems good. How do I check the tank check valve? I have held off on pulling the fuel rails to check the injectors for now. With the key on and engine running pressure is in the zone 55-62. Once the key is turned off it drops to zero. I can hear the pump running for a couple seconds when key is turned to on not cranking. Before the humm there is a clunk sound. Is there a thread here for lifting the bed?