fastfirebird

I have a 2000 silverado Z-71 with the 5.3 engine. It seems to crank forever before starting then after it first starts run a little rough for a few seconds but then all is good. It does this 99% of the time. It almost acts like it is not getting fuel but I have hooked up a pressure guage and I'm holding about 50psi with key on engine off. and around 40-45 psi while running. Any one have any ideas. I know this can't be the only Silverado that has done this. Please help. Thanks,Scott

carpenterbill

try leaving the key in the "on" position for 3-5 seconds before you crank it over

kcb37

Try turning you key forward and wait a couple of seconds, do that 2 or 3 times, then try to start it. That will let the fuel system prime. (build pressure)
If not that try your fuel filter. (cheap fix, and dosen't hurt to replace anyway)
Other than that I would guess a pressure regulator.
You might also want to check your plugs, and your air filter.

fastfirebird

I've tried leaving the key on for a few seconds before starting and it doesn't make a difference. I just replaced the fuel filter about 5k miles ago. How can I test the pressure regulator? If that was bad wouldn't that had shown up when I checked the fuel pressure? I will pull the plugs and check those and get back to you on that. Thanks for the suggestions keep them coming. I have to get this fixed I'm tired of the wife nagging. lol.

kcb37

You would have to look in a book to see how to check the pressure regulator.
I don't have a book that goes to 2000

NCHEVYHEVN

The 5.3s are horrible for building up carbon on the inside. I would really suggest throttle body cleaning.

Also I would really check to make sure your getting good fuel pressure. I'm not sure on the specs. but I'm sure its some where around 50-60psi. It doesn't take much for the motor to not have enough pressure either. It could be off by 5psi and that would cause a problem.

Also do you like to drive around with the tank almost empty? Their is sure way to kill fuel pumps since the fuel surrounding the pump actually lubes and cools the pump.

dragondad

I have a 2000 Silverado 5.3 and just started having a hard starting problem for the first time this past week. It started happening right after I changed the pcv valve. I don't know if it had anything to do with it. I would like to know if you fiexed the problem and how. Good luck and thanks.

kcb37

If your fuel pressure is within spec, start checking your throttle positioning sensor, advance, coils, and distributor. It wouldn't hurt to pull a plug and hold it on or very close to the block and have someone bump the starteer to see if it is getting good fire. I would assume it does as it still starts and I assume runs fine. I think I would bet on the advance, it should be a vacum advance but I am not sure. When you first start a car it will run rich, fuel injection runs 14 to 1 or 14 something, but to start needs to be a little richer, the timing will also advance so it will run smooth on inital start up. If your fuel air is a little rich as it should be but your timing is not being advanced that could very well be your problem.

NCHEVYHEVN

The 5.3s do not have a distributor. Instead they have 8 coils.

fastfirebird

Ok guys I need to bounce this off you. I pulled the vaccume line off of the pressure regulator( I think) On the drivers side on the fuel rail and their was gas there. Now this means my pressure regulator is bad correct. Thanks for the help