Engine/Transmission (1998.5 - 2002) injectors air locked? bad pump?

[Bill_L]

Other than the truck not starting what is the best way to tell if your injectors are air locked?



I was driving along in my truck today and pulled off to grab a little lunch from a drive through when my truck just stumbled and died. It would not restart.



I can bump the starter and here the pump run but the pressure is really low. . Only about 5 psi max and that is building up from about 2 or 3 when I first tap the key.



My injectors, comp, gauges, and weber fittings all went in a little over a week ago.



When I first got my truck back the fuel pressure was nice and high. . about 14-15 all the time. The last several days it has been about 11 to 12ish. .



Bumping the starter I get a small drip of fuel under the truck so there is a small leak somewhere that may have been bleeding pressure and let air in. I am un sure...



any ideas?



thanks.

 

[dsldoug]

fuel leak = air leak



doug

 

[Bill_L]

doug,



I had that part figured out thanks...

The thing that I am unsure of is if the air leak would cause an issue with the pressure like I am seeing on the gauge or if I may have multiple problems.



Bill

 

[rubberneck]

It sounds as though the lift pump may be going out. Obviously the leak needs to be addressed, but if the leak was bad enough to cause the pressure to drop that extremely, i wouldnt think the truck would run. Unless perhaps the leak is in front of the lift pump at which case it could be sucking air and losing prime.

 

[Lsfarm]

Fuel Level?

Bill L: How much fuel is in the tank? The higher the fuel level, the easier it is for the weak lift pump to pull the fuel up to the engine.



Suggestion: Fill the tank, and purge the fuel line by bumping the starter several times in a row [to run the lift pump], if the fuel pressure doesn't come up, change the lift pump.



You might be able to help purge the lines by opening the fuel filter drain until only fuel comes out, or cracking open a banjo fuel fitting after the lift pump.



I hope this helps, Greg L

 

[danandamy]

If the leak is on the INLET side of the lift pump, it could definitly cause your problem. If there is a leak before the lift pump, air is alot easier to suck than fuel and the lift pump will start sucking air instead of fuel, especially if the leak is bad enough for there to be leaking fuel noticable under the truck. This would also give you your low lift pump pressures.



dan

 

[Bill_L]

thanks for the info guys.

The truck has a half tank of fuel right now. I almost never even run it down to the point of the low fuel light coming on.



The leak isnt real big but I know it doesnt need to be in order to lose prime.



Since I am not diesel mechanic it is going to sit until one can take a look at it. I have other things to drive.



I only have about 3800-3900 miles on the truck so if the lift pump is dead I am going to be rather ****** off.

I have the full set of AN and weber fittigns so I figure one of them must have come lose. I know from working with them before that they can be a little touchy at times.



Bill

 

[Puffin Smoke]

Make sure your fuel drain isnt open slight or stuck. It happens!

 

[Bill_L]

Thanks for all the info guys.



I would like to spend a special thanks out to Mr. Blair Pine for find and fixing the problem in about 5 minutes flat.



I guess one of the new AN fittings had come lose and was sucking in air.



Bill