ok guys/girls I have a problem starting my truck only when its already warm....... im at a loss.. ok so heres the deal when I start the truck when its cold/sitting over night and I go to start it it fires up right away almost every time. but after I drive to walmart or whatever and go back out to fire it up the truck doesn't want to fire up until I tap on the gas pedal a couple times while cranking the engine. after doing so it fires up to a higher than normal idle for about 30-45 seconds before calming back down to regular idle. the entire time driving it it runs great. I have replaced the fuel pump twice thinking that was it. I have checked the fuel pressure regulator while the truck is running and it is not spitting fuel, I changed my air inlet temp sensor, starter, alternator, battery, spark plugs, wires, a couple injectors(had misfires), and fuel filter. I cannot get this truck start like it should and I don't know why. does anyone have any ideas?

 

year ,model, engine?

I would check for fuel lpressure leakdown. put a fuel pressure gauge on the fuel rail. if its not holding pressure it leaking either from an injector, fpr or back to the tank.

 

2000 GMC sierra slt, 2wd, 5.3ltr. what is fpr? but when I was replacing two of my injectors I checked to make sure nothing was leaking.

 

FPR is fuel pressure regulator. Look for a small round canister on the fuel rail with a hose attached (small). This is the regulator, if you pull the hose off it, and have gasoline out of it, the diaphram is bad, and it needs replaced.

 

Oh fpr oh ok I got it. Yeah I checked that and nothing's coming out. There has to be something else...

 

What is the idle rpm when it is "normal"?

 

Around 7-800 ish

 

how did you perform this check?
Why did you replace 2 injectors? Did you replace the orings? How soon after injector replacement did the starting issue occur?

 

The check was only visual but the reason i had to change out the injectors is because the truck was sitting for about 6 years so the number 7-8 injectors were all clogged up and I couldn't get them to clear up. Since I changed those out the misfires went away and when it is running it runs smooth.

 

I replaced the orings on those injectors only. Nothing looks to be leaking. And the starting issue was always there but is continually getting worse. It's getting harder and harder to start. And other symptoms are starting to come up, like after I start it it will want to die, the idle will not be consistent (almost like a puttering).