Hello everyone, a first timer here, a question for you: A good friend and I were talking about Dodge cummins diesels and he gave me this info. There is a pump mounted between the normal injection pump and the tank called the riser pump. Apparently this pump aids the injection pump in fuel delivery. His claim is that these riser pumps are prone to fail at around 100,000 miles and in doing so put an abnormal strain on the main pump eventually causing an injection pump failure! The reason] I`m asking is that I`m buying a 97 3500 dually tomorrow and this vehicle has 102,000 miles on it. The lady who owns the truck has no idea about any changes or replacements and I`m asking any of you if this is true or what!?
Regards, Richard

 

The pump he was refering to is a "lift pump" found on the 1998.5 and up Dodges with the VP44 electronic injection pump. The 97 that you bought will not have these issues.

 

Thanks Mcmopar, with less of things to go wrong this must be good news! The lift pump must however perform some kind of necessary function for the 98 1/2 on motors.I certainly won`frett over it.
Regards, Richard

 

Both trucks have them, the 1994-1998 truck have a mechanical pump that is driven off the lobe on the cam, the 1998.5 and up trucks have an electric one that is located on the engine or in the tank, and have proven to be a bit less than "great"

 

linwin - the VP (injector pump) provides high pressure fuel to the injectors. The LP (lift pump) supplys fuel from the tank to the VP. The LP's are maybe not the best pumps in the world, but the main problem is that they are packeged with the engine. Making them pull fuel, instead of push fuel (hend the slang name 'lift pump' it's lifting the fuel from the tank to the VP). That is a bad condition for durability.

A LP can fail slowly enough that a driver may not even notice it (without a fuel pressure gauge). It's the time duration that the LP is failing, that the VP may not be getting enough fuel to cool itself. The VP uses diesel fuel to keep itself cool. Starving a VP is not good. The VP will go kapoot real quick after its taken enough fuel starvation.

Your 97 will not have these issues, but I thought you may want to understand what the issue really is for the later model trucks (like mine).

 

Good info one and all, thanks
Richard