This time of year I may go up to 4-5 days without starting my truck. Lately, If I leave it for a few days, the fuel sytem looses it's prime similar to if you just changed the fuel filter. It will start, then stall. If you pump the primer lever 10 times or so, you can feel it squeeze the air out, then it will start.

I have all new fuel lines from the new module I replaced this winter right up to the pump. The fact that it's getting air should eliminate the possibility of a problem with the solenoid.

The only thing I have not replaced is the overflow valve. Is this common in a '96?

If so, where on the pump is it and where is the best place to buy one?


Thanks in advance!

 

Have you checked the electrical connection on preheater?

 

http://dodgeram.info/tsb/1996/14-07-96.htm The last picture is where the overflow valve is located.

 

You won't find a better price on an overflow valve than here but I sort of doubt it's the problem. Best bet is to pressuize the fuel system to no more than 10 psi with compressed air though the tank fill and to listen or soap for a leak.

Precision Diesel Injection and Turbo Inc.
Marty Tompkins
888-734-7349
$35 + $7 shipping and handling.

Replacing the OF valve is a five minute one wrench job if you don't drop the sealing washers, stuff a rag under the valve to catch a falling washer. Remove the old valve and put new one in it's place. Occasionally the notch in the manifold you see to the left of the OF valve in the picture needs to be filed or ground a little to allow the old valve to be removed. Don't bend the line to remove the valve, it will make it very difficult to line up again. New style OF valves don't always have the retainer on top that says not to remove, don't worry it's just a design change.

The object in the lower left corner is the oil fill cap.

 

If it is leaking at the heater, if I remember correctly it would be the element connection, not the themostat connection. The upper connection is the t-stat (I don't think this actually could leak fuel because the t-stat has no actual opening or exposure to the fuel?)

So, if it is the element connection, whats the cure. can I remove just the plug and get a new gasket?

 

A couple of years ago my neoprene fuel lines deteriorated enough to let fuel drain back. Look at those lines real good.

 

Infidel...is that a Cummins part?

 

where are the neoprene lines? i replaced the lines from the tank to up behind the brake booster. this looked like all the rubber line that was on there except for a little 90 on the fuel strainer. which i replaced too!

 

Did you also get the return line that goes behind the fuel filter and hooks up underneath the injector pump? That's the one that I think usually gives the most problem. Maybe because it's so close to the block and higher temps? If you replaced 2 lines then you got it. Might just check your clamps and make sure they haven't worked loose or anything.

 

I replaced the lines with the marine fuel line and that seemed to help my problem thats similar to the above mentioned. Although sometimes on rare occasions it will still start for about 5 seconds and then stall. Then I need to completely prime it in order for it to start again. It seems to do when parked on inclines mostly. One thing I have noticed is the "squeak" noise is gone from the overflow valve when I prime it. Is that a potential problem? Or lift pump? Im lost. Thanks

 

Makes me wonder if you are about to lose your lift pump. I believe if I started having problems like that I might look at putting on a Fass or Glacier pump. But it may be that you could try to rebuild the stock lift pump.

 

The truck and entire engine has 173K on it if that makes a difference. The lift pump does seem to have an odd feel to it now when priming. Its sort of got an airy feel to it, like its pumping more air than fuel but it does prime the system. And I think that overflow valve is no good seeing the squeaking noise is gone.

 

Any clues? Im lost

 

Is there any fuel collecting on the liftpump? There are two rubber Orings inside that can be replaced. Is the fuel filter on tight? I know it was mentioned all lines were replaced. Did this include the preheater to liftpump soft line? On my 96' this soft line had extensive dryrot. Is the fuel preheater tight? The gasket in the fuel preheater can rot. The gasket and new strainer are cheap from Cummins.

I read somewhere some time ago someone had problems with the soft lines back at the tank. This is a rare event. They were dry rot. Has anyone messed the injectors? Are they tight?

 

If you've checked everything else, I would think it's either the overflow valve, or a check valve in the lift pump isn't sealing. I've seen both cause this problem.