Engine/Transmission (1998.5 - 2002) another pump??

[wrichards]

I have two lift pumps on my truck and drive by the guage. One of my employees took the truck in june and the pump on the rail failed causing the truck to stop. When I got to check it I discovered the problem and bypassed the pump using the engine mounted one. At that time i had the 0216 code. Continued to drive the truck no problems until today. Loss of power and blue smoke. When cold truck runs perfectly but after 5 miles or so it acts up and will only go about 10 mph. This is my 4th pump unless you guys have another suspicion- getting old.

 

[wrichards]

help me out here, towing to shop on monday would love to know what i am talking about. Also by now there should be a place to get a pump remanufactred that most of you guys desire. I already have a fass lift pump engine mounted putting out 18-20 psi.

 

[VolsFan]

Wow, what a great resource to have BSeyler. Hopefully I will not need it for a long time though! Also, wrichards, depending on where you are located, I had a nearby diesel shop replace my original VP, under warranty for one year as long as the wire wasnt tapped and not determined to be run low on fuel pressure. Well sure enough, right towards the end of the year warranty, pump died. Had not been tapped and fuel pressure was always above 12 psi. Replaced it and didnt charge me a dime. That was about five yrs ago, no problems since. So to anybody thats local to me I always reccomend that place.

 

[wrichards]

ok thanks for the help. Well truck has been running fine now, but every once in a while the lift pump pressure crashes and than truck almost dies. Shut truck off, wait five minutes and fule pressure comes back up. I also tried to bump the starter to get the lift pump to run when this happens and it won't. So my squestion is what controls the lift pump? Just 12v wiring or the pcm/ecm.

 

[JLandry]

I also tried to bump the starter to get the lift pump to run when this happens and it won't. So my squestion is what controls the lift pump? Just 12v wiring or the pcm/ecm.

The lift pump is powered directly from the Cummins ECM with no fuse, no relay, nothing else in the circuit! See THIS POST for more information on lift pump wiring. It seems like a questionable wiring design, but based on the low percentage of failures overall, I guess it's worked pretty well.



Anyway, if you're powering two lift pumps off the original wiring harness without the aid of a relay setup, then you may be overloading and have already damaged the ECM's circuitry.



A work around to power the lift pump(s) when the ignition key is turned on can be found in THIS POST. This will work even if the original ECM lift pump circuitry is damaged. With this arrangement, there'd be no load carried by the ECM circuitry, and anytime the ECM powers the VP44 fuel injection pump, the lift pump(s) will also run.



Best regards,



John L.

 

[wrichards]

thanks for the response on the lift pump and additional relay. I am not that good with electrical but have wiring skilss. Where is a good place to buy the relay and can you give more instruction on what wires to connect to? I think this is the problem as truck intermitently looses pressure on a 1 year old ddrp pump from fass.

 

[JLandry]

thanks for the response on the lift pump and additional relay. I am not that good with electrical but have wiring skilss. Where is a good place to buy the relay and can you give more instruction on what wires to connect to?

Here's a really nice relay sold by Geno's Garage: Waterproof Relay Kit



Radio Shack or an auto parts store is a good place to get things like relays, fuses and fuse holders.



The wires you need to connect to are identified on a wiring diagram in a post I linked to earlier in this thread.



If you're not sure you can do this type of project on your own, the best thing might be so solicite the help of a friend who can help you identify the wires as shown in the wiring diagram. The diagram shows you the colors and gauges of the wires you're looking for (e. g. : a brown and white 18 gauge wire coming from pin 36 of the ECM's 50-pin connector).



Best regards,



John L.