Lousy starting 5.3 V-8

[dhspring]

My son's starting problem hasn't totally gone away on his 2000 Silverado, 5.3 liter V-8. We replaced the fuel pump and fuel filter and have 55 psi at the check port. It still doesn't start like it used to. We used to be able to turn the key without hitting the gas pedal adn it would fire right up and idle at about 700 rpm, now you have to pump and crank and kind of work to start it. When warm it might crank right up or not. I checked the plugs they look fine, there is 78000 miles on the truck. The check engine light does not come on, I checked for codes, none come up with an engine analyzer. So something is still amiss but it is subtle. The truck drives normal on the road with normal acceleration, no missing or anything, it's just at startup where the problem it.

Has anyone else had this problem or any ideas? Thanks very much!

[zirb]

See if you got any corrosion inside the dist cap. Might be cross firing in the dist.

[RahX]

no the idle control on that truck is controlled by a motor due to the fact that there is no throttle cable anymore. clean the throttle body and im very sure thatll fix your problem. its gonna be tricky but I *think* you can gently open up the throttle plates with your fingers, DONT FORCE THEM, if they dont want to open with moderate pressure just clean them the best you can. you might also have someone in the truck with the key on and their foot planted to the floor to open it all the way, not sure if thatll work or not but it might.

[pipe539]

I had that problem it turned out to be the fule psi regulator. I found it after i shut it off and pulled off the vacume line and there was gas in it. If you check it just after you shut it off you might not see anything, But try it again and let it sit for 10 minits and then look.

[BlenderWizard]

Originally Posted by zirb

See if you got any corrosion inside the dist cap. Might be cross firing in the dist.

Originally Posted by RahX

no the idle control on that truck is controlled by a motor due to the fact that there is no throttle cable anymore. clean the throttle body and im very sure thatll fix your problem. its gonna be tricky but I *think* you can gently open up the throttle plates with your fingers, DONT FORCE THEM, if they dont want to open with moderate pressure just clean them the best you can. you might also have someone in the truck with the key on and their foot planted to the floor to open it all the way, not sure if thatll work or not but it might.

Don't spend any time looking for a distributor on your truck, because it doesn't have one. Also, your truck DOES have a throttle cable, because GM kept those until the 2003 model. I would think that pipe might be on to something with the pressure regulator.

[Frank Niemiec]

Originally Posted by dhspring

My son's starting problem hasn't totally gone away on his 2000 Silverado, 5.3 liter V-8. We replaced the fuel pump and fuel filter and have 55 psi at the check port. It still doesn't start like it used to. We used to be able to turn the key without hitting the gas pedal adn it would fire right up and idle at about 700 rpm, now you have to pump and crank and kind of work to start it. When warm it might crank right up or not. I checked the plugs they look fine, there is 78000 miles on the truck. The check engine light does not come on, I checked for codes, none come up with an engine analyzer. So something is still amiss but it is subtle. The truck drives normal on the road with normal acceleration, no missing or anything, it's just at startup where the problem it.

Has anyone else had this problem or any ideas? Thanks very much!

HAd the exact same problem. Was the fuelpressure regulator. Easy to replace. One clip and a vacume line. Cost me $60.00 at Advance Auto parts. Been starting fine for the past month now. Like one of your replys look for gas in the vacume line when you pull it off.

[scannr89]

I have seen the pressure regulator go bad many times,,the diaphram ruptures allowing pressured fuel to go straight into the intake vacuum port, this floods engine with raw fuel as pressure goes down, worse it seems when driven a short distance then shut off and restarted,

[dhspring]

Thanks to all who responded, I got it fixed, it was the fuel pressure regulator. Now I'm pissed that I changed the fuel pump and it was the regulator the whole time. Oh well, dem da brakes in auto repair work. That regulator is extremely expensive, it looks like a $10 part and about the size of a golf ball, and I paid $65 at Autozone.

For whoever suggested the distributor, one guy was correct who responded, there isn't a distributor on these late model Chevys, only coil packs, and there is a throttle cable still. So if your Silverado starts poorly but runs well on the highway, immediately suspect the fuel pressure regulator, you don't even need a tool to replace it.

Merry Christmas to all!