2003 Dodge diesel 3500 sometimes starts ,but not always after driving a short distance and cut it off it will not start. Sometimes you can the fuel filter top off and screw it back on and it will start. One guy told us it could possibly be the vacuum line, have also been advised it could be the fuel pump inside the tank. Any ideas?

Hi Mickey,
First thing you need to do is make sure you have no air in the fuel system, and because you said that you removed the top of the fuel filter, then chances are you have air in the system now.With diesel engines they don't like air trapped in the fuel lines to the injectors, so it will start then cut out.Remember, diesels don't have spark plugs, so they just fire due to compression.
So you should do the following:1. Have the fuel system bleed of all the air.If you still have the problem after this is done.
2. Have the fuel cut off solenoid checked to ensure it is not faulty.
If you need further information please let me know.
Thanks
Jason

Thank you for the direct question. Although I have been to the diesel school, it has been years since I have worked on one, so don't know how good my advice will be.

In one way you sound like you are fuel starved, but taking the top off the fuel filter and putting it back on would have no effect if that was the case. But you should do a fuel pump pressure check just to make sure.

A vapor lock sounds like what your problem is. That would expain why opening the fuel filter up would enable it to start. Check your vacuum lines and make sure that everything is connected.

Would check fuel lines for dirt sounds like fuel starvation also check make sure your tank is vented