[ehorn]

I have a 2005 Suburban 1500 with the 5.3L engine with 60k miles. I'm experiencing hard starting right now, I had it in at my mechanic and he replaced the battery and starter thinking that was causing it. It is still doing the same thing.

What its doing is you crank it once and it won't start, on the second crank it starts up almost right away. I did some searching online last night and saw that a fuel pressure regulator can cause hard starting. Is this correct? Is there something else I should be looking for?

Thanks,
Eric

 

[GMfan1111]

could be we had to replace a fuel pump on my moms 02 suburban 1500 while we were up north with our trailer. except in our case the suburban would start good but then refuse to go above 50mph and then eventually stall (Imagine how scary that is when your towing a 26 foot long camper at the same time). still its a good bet to check the fuel pump and fuel pressure regulator for anything out of the ordinary

 

[shadams]

If I had to put money on it I would say fuel pump. I say that because when the ignition is turned on, the fuel pump is turned on and the fuel line is pressurized for starting. Then the vehicle stats and you go to work or whatever. When the vehicle is shut off there is a check valve of sorts in the pump that keeps fuel pressure at the lines for starting next time. If that valve leaks, then the fuel bleeds back into the tank and you have to cycle the key a couple of times to get the fuel back up to the engine.

The regulator could cause the same issue if it is leaking, but when they leak the fuel gets to the vacuum side and then when started gets sucked in through the intake which would cause other issues such as running rough after starting, ses lihgt due to rich fuel mixture or smoke, so thats why I am leaning toward the pump.

The right way to find out is to install a fuel pressure gauge, see what happens when the key is turned on and its started, and see how fast the pressure drops after its shut off, and visibly inspect the regulator for signs of leakage.

 

[ehorn]

Thanks for the input, I greatly appreciate it. I'm going to have my mechanic look into that. I don't have the equipment to do it myself. I'll let you know how it goes, but sounds like on the right track at least. Just amazing how sometimes it starts up fast and others it doesn't which does kinda explain how it could be a pressure problem in the lines on start, but once it's going there is no problem. Haven't seen a dramatic drop in fuel mileage so no fuel loss as well.

Thanks again and if anyone has more input I'll gladly take it.

Regards,
Eric

 

[328Nero]

I am having the exact same isse with my 2005 Z-71 Sub...can you tell us what the culprit was?

 

[Billy_Bob]

Actually there is quite a bit to the fuel system. A LOT more than just the pump.

There is the regulator and also a "check valve" which prevents the fuel from draining back into the tank when the engine is shut off.

If it is a problem with the check valve, I would imagine it would take a while for the gas to drain back into the tank. So in theory, it you tried restarting it right away after running it, it should start right back up.

Then get progressively worse as you add more time between running and trying to restart. (Up to the time it takes for all the gas to drain back into the tank).

Anyway here is a good list of things to check for fuel system servicing...
http://www.asashop.org/autoinc/june98/techtotech.htm

 

[bgulledge]

Can you tell me where the fuel pressure regulator is located on a 2005 1500 Suburban? I downloaded a picture of the regulator from the web and it looks like a small shiny metal canister with a tube connector or the side, but I can't find where it is located on my engine. I removed the large black plastic cover (about 10" x 20") on the top of the engine, and removed the small hard plastic cover underneath, at the top rear of the engine, but I still don't see anything that looks like the fuel pressure regulator in the picture.

 

[MrCritical]

What year did they do away with the external fuel filter?

 

[53chevy]

05 Sub uses a returnless system, fuel filter and regulator are part of the sending unit in the tank. The best thing you could do is hook up a pressure gauge and monitor it. Make sure the air is bleed out first. Operating pressure spec is 55-62psi turn off the engine and monitor it for 5 min, if it drops more than 2psi youneed a new sending unit.