My older truck has a habit of getting air locked after it has been running for a while, I shut it off then it won't start unless I crank on it. I can't seem to find where it is sucking the air in at. Any advice on where to start looking for the leak or any advice would be greatly appreciated. Thank you

 

I've seen quite a few cases posted where the rubber fuel return line had cracked due to heat & age near the back of the head.
Numbers 2 & 9

 

I have looked at it and can't see anything wrong where it could get air in it except maybe that quick connect fuel line thing. Is this a job that would be eaiser to take it to my local diesel shop rather than crawling under my truck all day? It only seems to get air in the lines when it has been running a while then it starts missing like it has air in it.

 

It's definitely no problem to replace the line that goes to number 3 (comes from the fuel tank) with a 10mm id rubber hose.

But the question is- will it fire right up after you've let it sit over night? If yes it usually isn't air in the lines, it's the VP44....

AlpineRAM

 

My guess is not the vp-44 it runs just like the other one did when the mechanic forgot a washer when he put on the lift pump and it was sucking air in the lines. I will never take any of my trucks to another dodge dealer again every time i go there for a warranty issue they prove how much they don't know. It is going into the local tractor mechanic in the morning if I can't pin point it today.

 

If your filters are clean, all the fuel hoses have been replaced in the last couple of years, and all your banjo fittings have their sealing washers; then take a look at the overflow valve on the VP itself. They sometimes fail and allow the pump to lose prime when sitting.

Another all too common problem is the internal bypass valve in the lift pump will stick and allow fuel to drain. That is generally noticable when you first do the starting sequence and the fuel pressure does not immediately pop right up where it belongs.

The best approach to identification of the problem is a fuel pressure gauge on the outlet side of the filter housing. That will tell you if you have pressure to the VP.

However, your problem sounds to me like the timing port on the regulator for the injection pump delivery valve has eroded. If that is the case, the VP is failing and will soon quit. If the problem happens more often in hot weather than in cold weather, this is almost always the cause.

 

I just got done replacing the fuel plastic fuel lines, now there is no more air bubbling out of the filter housing when I crack the 7/16 bolts on top. And the better news is its starts every time. I'm still going to have it looked at tomorrow its better to have something wrong with it now when its in the 70's outside than when its -10 this winter and trying to fix it then. Thanks for all the great advice.