Alrighty got some questions regarding some hard starting issues I have been having. For about the past two weeks or so my truck has not been starting on the first crank, but always on the second one. So I have just been cycling the key twice and it works fine. Last week i replaced the FPR with a new ACDelco one and also replaced the TB gasket for good measure. Today I hooked up a fuel pressure gauge and this is what I got. Cycled key on and the gauge jumped to about 50 and just bleed down to 0 within 10 seconds or so. Turned the truck on and it went to about 48 psi and held steady and didnt change with engine RPM. I replaced the factory fuel pump about 2 years ago with a advance auto part and it has done the trick, but have been reading these do not have the life span of a Delphi unit. Any guidance to which way to go or tests to see if I have a leaky injector or its time to replace the pump again. Truck is a 2000 silverado with a 4.8 that has a little over 235K on it.

 

Does it do it all the time?

 

Yeah pretty much if it sits for more then say an hour or so it will not want to start on the first crank.

 

Well I would suspect the pump or injectors. Just had a bad injector on my jeep that did the same thing. I just pulled the fuel rail with the injectors still in it, placed rags under it to keep anything from falling in injector holes and sat some cardboard under injectors to see if they leaked. Obviously cardboard turns dark brown so its easy to see which one is leaking if any. If any leak then you know which ones are bad, if none do then most likely a bad pump. Just my .02

 

I'd say check valve in pump is bad, but you check your fpr by pinching the hose with a pair of needle nose vice grips.

 

Ahh ok i will pinch off the line tomorrow and give that a shot and see what happens. So if the pressure hold with the line pinched then that pretty much narrows it down to the pump.