2000 5.3 won't start - not fuel pump!

[TajoeMang]

Hey All,

Have 2000 Tahoe with 5.3 and 225,000 miles. She runs VERY well, is super reliable and idles at 550 smoothly. Noticed trouble when starting before she completely stopped starting a couple of days ago. Had to turn over several times before it would start, and now nothing happens when I turn it over. Acts like it wants to start and almost does, before stuttering off. Acts exactly how a bad fuel pump would before I goes out completely.

I replaced fuel pump last year and the gauge currently shows 58 psi when I turn the key and then 55 psi when trying to start, so this cannot be a fuel problem, right?

I also have already replaced both the crankshaft position sensor AND the coolant temp sensor. Still, no starty. HELP, don't know where to go from here, thanks and Merry Christmas.

 

[George B]

Does the fuel pressure leak down? Pill the vacuum hose off the fuel pressure regulator and check if fuel is present. It shouldn’t be.
Have you checked for spark?

 

[mpope2]

Had the truck been sitting for a period of time before no start issue?

 

[OR VietVet]

Does the fuel pressure leak down? Pill the vacuum hose off the fuel pressure regulator and check if fuel is present. It shouldn’t be.
Have you checked for spark?

My first thought as well. Got to have 3 things for an engine to start, fuel, spark and correct timed compression. Do you have spark when the rig is not starting?

 

[clandr1]

What brand fuel pump did you use? My original fuel pump was fine, but the built in fuel pressure regulator (a check valve, essentially) would allow fuel to leak back down into the tank which cause issues with starting the truck.

Try this:

Turn the key on but do not crank. Take note of the fuel pressure reading immediately. Then, DO NOTHING - wait 3 minutes and see if the fuel pressure drops (it shouldn't). If it drops, then a FPR is likely the culprit, and on my 2005 it is built into the pump itself - yours might be built into the fuel rail on the top of the engine.

 

[George B]

What brand fuel pump did you use? My original fuel pump was fine, but the built in fuel pressure regulator (a check valve, essentially) would allow fuel to leak back down into the tank which cause issues with starting the truck.

Try this:

Turn the key on but do not crank. Take note of the fuel pressure reading immediately. Then, DO NOTHING - wait 3 minutes and see if the fuel pressure drops (it shouldn't). If it drops, then a FPR is likely the culprit, and on my 2005 it is built into the pump itself - yours might be built into the fuel rail on the top of the engine.

His is in the fuel rail.