What is this?

[JBfoot]

Ok, I can't seem to figure this out. My truck always takes two trys to start. The first it turns over, but then quickly dies without hesitation. The second time it starts, may hunt for a good idle for a few seconds, and then runs fine, actually great. If it sits for a few minutes, maybe 5 minutes, the same thing happens. I have a new stepper motor, new Mallory distributor, new coolant sensor, and replaced the fuel pump relay. Not a big deal, but still a nuisance. Any ideas?

[Overlander]

it sounds to me like your fuel lines are not maintaining prime. when it sits, the fuel starts working it's way back to the tank from the engine, then when you start it again, the fuel pump has to push it all the way back up, which takes a few seconds. In the meantime, the engine is running very lean or dry. Once it runs, the fuel lines are primed, and it will start again right away. I would suspect that your fuel pump is either not cycling correctly, or there is a small leak in the fuel line, likely in the pump. But that's just one enthusiasts opinion.

[dmarchand]

Sounds like a fishy pump. Prior to the first start, when you turn the key halfway, do you hear the whir of the pump? What happens if you leave the key halfway for 30 seconds and let the pump prime for a longer period of time?

[JBfoot]

I hear the pump whir for a few seconds, maybe 5, then stop. I've tried waiting before, but not for 30 seconds. It did start on the first try after 30 seconds. Does that mean impending pump failure? Should I replace it or just put up with it?

[dmarchand]

I believe you have three possiblities:
1) leak of some kind - need to check fuel pressure
2) blockage - when did you last change the fuel filter?
3) pump on its' way out

[JBfoot]

Filter is new. Could there be air in the line causing this. Is there a way to check and/or bleed the line? Thanks.

[Overlander]

The fuel should not be slipping past the pump and back in the tank if the pump was good. Can I get an Amen? I think it's new pump time.

[JBfoot]

The fuel should not be slipping past the pump and back in the tank if the pump was good. Can I get an Amen? I think it's new pump time.Well crap......I mean, Amen!

[Lesandjes]

I wouldn't immediately assume that your fuel pump is bad. You should check pressure at the rail after you turn it off and see if it holds pressure for some time after the engine is off and the pump has stopped. If pressure drops way down within a few mins, than you may have a leaky injector causing fuel to leak out of the pressurized fuel rail.

Just something else to check first.

AndrewT

[Tawayama]

He should have a spare Carter pump anyway...even if he doesn't think the pump is bad. No spare fuel pump = trouble with LR's of this vintage. Spare's are cheap and plentiful. Go to NAPA and discover a whole new world.