350 Vortec trouble starting.

[socalfandabodys]

I have a 350 Vortec engine in my 1999 GMC Sierra 2500 Classic and it has recently started having trouble starting. It is usually not on the first start of the day but, after you shut it down for a little while. It won't start on the first crank, usually on the second and then it idles very weak for two or three seconds. After that it idles fine and smooth right at 600 rpm. I have tried running fuel injector cleaner and that doesn't help. I also replaced the fuel pump and filter recently. Do you think it needs new injectors and if so how hard is it to do? Thanks and any help is appreciated as it is my daily driver.

[LSXfan]

maybe fuel pressure regulator..i'm bettin it's the pump

[EFI69Cam]

cam sensor?

[MonzaRacer]

I would almost bet the fuel spider has sticking poppet valves if its CPI, I have access to local AC Delco dealer and they go for around 399.

[LSXfan]

clear your PM's socal

[wedgehead]

I would recheck fuel pressure. See if the pressure bleeds down after you shut engine off. fuel pressure regulators do leak on these. They can be bought aftermarket,very easy to change, under plenum mounted on side of injector assy. If its not leaking down, fuel pressure must be 55 lbs or will have problems starting. have seen these engines have 50 lbs and have starting issues.

[71RS/SS396]

I'm betting the fuel pump, I had the exact same problem 6 mos. ago with my Tahoe. New pump cured it.

[socalfandabodys]

When you had the problem with your fuel pump could you still hear it running? I have had the fuel pump replaced in the past and it has lifetime warranty parts and labor so it may be time to go visit the dealership.

[71RS/SS396]

Yep,only had the problem if it sat for a few days. If I gave it a shot of ether it would fire up. If I drove it everyday it was fine. Seemed like it would lose it's prime then was a pita to get started.

[socalfandabodys]

Thanks for all the help. I will let you know what it is after I do some more trouble shooting this weekend.

[megaladon6]

it may simply be the check ball in the sending unit/fuel pump. put a pressure gauge on over night and see how long it takes to bleed down.