95 dodge 3500 2 door dully diesel. will start good for about 2 weeks. then its dead all it will do is crank but never fire. we loosen the ejector lines and crank it until the air is out and fuel comes out tighten the lines. then it starts great another couple of weeks then we do it all over again. where is the air coming from, and how do i stop it?

 

start by looking over all your fuel lines from the tank to lift pump and from there to the filter assembly and then injection pump, how is the fuel filter, and how long does is set before it wont start. also if it doesnt start if you open the fuel cap does it hiss like the vent tube might be plugged on the top of the tank. i have seen any number of things cause that situation, but i would lean towards fuel line issues likely between the tank and lift pump or a plugged vent tube. also check the return pressure regulator on the pump, its the bolt that holds the return line to the pump it has a spring inside that can get weak or break, but will usually make the truck idle rough and run badly.

 

at the back of the engine driver side there is the fuel supply line, I bet you have a leak in it right in there. I would just replace all the rubber line and be safe. you may not see a sign of a leak as it is under suction but they leak in that area after a while....easy fix.

you are sure the shut off sol. is working right

 

Most common cause is the line in red below. Replace it with diesel rated 5/16" hose. Two feet is more than enough.