Engine/Transmission (1994 - 1998) injection pumps

[DPyles]

Hello everyone, it has been a while since I have posted and I would like a little info on the different injecton pumps used on these Dodge diesel trucks. I believe the first gen. trucks had a "distributor" type mechanical injection pump and the 2nd gen. have an inline style bosch mechanicaly driven pump. Does the 3rd gen. have a mechanicaly driven pump or is it electronically controlled? What is the difference in the "common rail" injection systems in the new trucks? Are they similar to the gasoline fuel injection systems? What are the signs of a mechanical pump going south? Has anyone ever rebuilt one of their own or is this not for the home mechanic? I understand that they operate on tight tolerences and need to be bench flowed and tested, is this correct? Are all the mechanical pumps working in the basic same principles and using similar parts?

Just curious bout these things and would like more knowledge on this subject.

 

[chrleb1]

You are pretty much right. The 3rd gen pump is driven by a gear but controlled electronically. This is a common rail setup. Basically the fuel comes out of the pump in one tube and then is distributed to the injectors. The injectors are electronically controlled also. This is what makes them quieter at idle (retarded timing). I believe a box changes the pressures at what the pump operates and changes the injector timing when on the throttle. The p-pump (2nd gen. ) is an all mechanical pump. I believe it is the most dependable and most powerful. It is technology that has been around for a long time and well refined. It can be rebuilt easily with the right tools. It also does to have to be flow tested when finished for fine tuning. We built one, but we had a friend that ran a diesel shop. You can think of the p-pump as a small motor. You can change the cam, piston size, delivery valve size, and so on. That just a little info.

 

[BV]

And in addition to that - The 24 valve engines from 98. 5-2002 had the Bosch VP44 Electronic Fuel Injection Pump. This is considered by some as the 3rd generation engine that was used in the 2nd gen body style. This pump is gear driven like the others.



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