I go out this morning and truck starts up as usual and I set my "high idle" at ~1150. Get out to brush off the snow and shortly after, it starts running rough and then quits! Huh....... NEVER did that before. So I try to start it again, but it will only fire intermittently. Seems to want to start if I hold the throttle down a bit. Like it's out of fuel, but I still have over 1/4 tank. Get out and try priming it with the button on the pump..... no real difference. Lossen filler cap and hear air movement like there was a vaccuum in the tank ( I've had that before.) Try and start now won't even fire!

Go see my diesel tech and he says and I have to agree that it sounds like lift pump and he can change it tommorrow. $$$$$

Go home, bleed fuel filter by prime button etc. Get lots of air. Loosen #1 injector line and go turn it over and over and over. Finally starts and seem to be fine now. I've never heard of a mechanical pump being intermittent, so open to suggestions as to what's going/went on. Obviously it stopped getting fuel for some reason, but?????

R...

 

is it gelled?

 

I'm not sure if this applies to your year but I've read several threads on here about the flexible rubber fuel lines cracking and letting air in the system. If I remember right the lines are somewhere between the steel lines on the frame and the engine but don't quote me on that. Do a search for "cracked fuel line" or "cracked rubber" etc.

 

I don't THINK it was gelled. I'm using Stanadyne Performance additive and it was only about 22 degrees (-9C) Could be the hoses, but why did it correct itself??

R...

 

It only takes a little air to cause the pump to stop pumping. You bled the air. Assuming it is the hoses letting air in, the hole/crack must be small enough to have not allowed enough air back in (must not have flexed in the right direction or not allowed to sit for enough time, etc.).

 

It is rare for a 12V lift pump to fail and I doubt its cold enough to gel (could you have gotten a bad tank of fuel?). I would bet that you have small holes in the rubber fuel lines, which were already mentioned, and the holes are allowing air in and you are losing prime.

In most cases you wont see any holes and you wont even see any fuel leaking. This is the first thing you should look at and if you havent changed them before - its time. Its a bad enough job when its warm - will be a real treat in the cold.

 

Well, it's been a few days now and no more problems, go figure. I guess I'll just hope for the best until spring and then change the hoses anyway.........

Thanks for all the help,
R...

 

Rick - another thing to look at is the overflow valve. Theres some info here:

http://www.dodgeram.org/tech/dsl/tro...p.htm#Overflow

http://dodgeram.info/tsb/1996/14-07-96.htm

You can pick up an overflow valve at Cummins West Edmonton. Talk to David at the parts counter.

 

Thanks, Dr. Wonder what they're worth??

R...