I can’t get a break. There goes my fuel pump at 165k

[LordWayback]

I went to start my truck and it won’t start or stay running unless I rev it to Atleast 900 rpm I tested my alternator and battery. God bless it fast idle stick

 

[LordWayback]

Alternator charging Atleast 13.5v almost 14v battery is a 2021 and reading 14v. I’m screwed.

 

[rockola1971]

If your fuel pump was bad then the engine wouldnt start at all.

 

[OR VietVet]

Lots of things can cause your rig not to stay running. The fuel pump could be going out and is weak but if is running as long as you hold the pedal down, well now we have a can of worms to think about. Any CEL's? Just so I don't and other members don't ask later, what is your year of Yukon?

 

[Doubeleive]

fuel pressure check is needed for beginners

 

[LordWayback]

If your fuel pump was bad then the engine wouldnt start at all.

If it’s going bad it won’t stay running I’m a diesel mechanic and that happened on our 1998 international 4800 the mechanic quoted $2,500 for tons of electronics and labor 3 hour fuel pump job and it’s still running

 

[LordWayback]

Lots of things can cause your rig not to stay running. The fuel pump could be going out and is weak but if is running as long as you hold the pedal down, well now we have a can of worms to think about. Any CEL's? Just so I don't and other members don't ask later, what is your year of Yukon?

I dealt with another cel earlier today but it’s a evap code cleared and staying gone. and it was just a gas cap nothing else diagnostic code wise 2001 Yukon XL SLT 5.3, under live data I believe the scan tool said I was running a little low on fuel pressure but not in the danger zone that’s why I’m thinking fueling because once you give the pump more voltage aka throttle input it stays running.

 

[LordWayback]

fuel pressure check is needed for beginners

I don’t have the tool for it but the scan tool gave me a diagnostic fuel pressure reading I don’t remember the number but I remember it being low but not in the will not work pressure zone everything is checking out electrically. I can change the relay but besides that I have a good intake filter (replaced 2k miles ago still white). I’m getting spark At least enough to not give me a issue before today, that leaves fueling or something along the valvetrain like a cam position sensor but usually when those go out it won’t start even if you give it gas., I know my fuel pressure is low because I had it tested because I have cold start problems but I just ignored it because it isn’t 25* outside so no worries about cold starts.
Is there something else that’s a issue besides old plugs , electrical , fuel pump that would cause this it was idling just fine a few hours before and my voltages check out.

 

[LordWayback]

Lots of things can cause your rig not to stay running. The fuel pump could be going out and is weak but if is running as long as you hold the pedal down, well now we have a can of worms to think about. Any CEL's? Just so I don't and other members don't ask later, what is your year of Yukon?

It wasnt a single problem besides low ambient temp starts before today and it was idling today just fine. I shut it down and now it only runs with the fast idle stick , no weird noises, no huge misfire, no CEL, I’m kinda lost if it isn’t fuel pump related considering the voltage is fine .

 

[LordWayback]

Last thing I didn’t list is a possible fuel pressure regulator issue causing the fuel to not be pressurized enough to idle without givin her a little beans for idlin