Engine/Transmission (1994 - 1998) Fuel bleed back??

[CumminsPower98]

My cousin's '97 is having a fuel bleed back problem that comes and goes. To start with I replaced both the lift pump and the overflow valve because both were found to be leaking internally. This helped but it would still bleed back a little bit sometimes. The next step I took was to replace the rubber return line and the fuel heater screen/o-ring. After all that it ran fine for some time and now he reports that it's bleeding back really bad again and he has to prime it for a long time and still has a hard time starting it. What have I missed here? There are no visible leaks and it runs fine. Makes me wonder if one of the new parts is failing again or if a piece of dirt or other debris got in something. Any new ideas?



Mark

 

[illflem]

If everything else checks out

Sometimes the self tapping screws used in the fuel tank module can wear a hole in the internal lines causing an air leak.

Most times, but not always, this causes a problem only when the tank is below a certain level

 

[rjones]

Hey Bill, where do you come up with all these great answers?Cummins or Dodge should hire you to solve some of their probs

 

[GSchroeder]

I had a '98 in that had broken fuel tank sender bradket in the tank. It rubbed a hole in the pickup tube and sucked air. The module costs about $300 so I fixed the bracket and put in a rubber line. Be careful to make sure the anti-drainback valve is in properly.

 

[CumminsPower98]

Thanks for the replies. I was coming to the fuel tank module in my head so now that it has been suggested I will pull it and take a look. I wish I had done that now when we were swaping his bed out for another one. I even looked at it and told him this would sure be the time to change the fuel sender if it was acting up. The fuel level and the parking angle for sure made a difference before changing the pump and overflow valve out. not sure if it does now or not.

 

[illflem]

Originally posted by rjones

Hey Bill, where do you come up with all these great answers?Cummins or Dodge should hire you to solve some of their probs

Unfortunately when my 3500 was new it had a fuel delivery problem. I took it to eight different dealers and every part of the fuel system was replaced eventually under warranty including the injection pump.

Friend of mine who is a bus mechanic finally figured out the hole in the module problem. When I approached the dealer with this they hemmed and hawed, said it wasn't possible. They finally said they would pull the module but if it wasn't the problem it would be my buck, they ended up paying.