Greetings: [that's how the old draft notices began for those of us old enough to recall!]

After the demise of my venerable 1988 Dodge work truck, I joined the Cummins Diesel club by purchasing a 1996 12V 5-speed truck from an older gentleman.

A good fishing buddy, who has a 98' 24V, warned me about the necessity of installing an LED low fuel pressure warning light to indicate the untimely event of a lift supply pump failure. I noted, however, that of the low fuel pressure installation kits I saw, they were all intended for the the 1998 1/2 plus year Cummins that used a VP 44 model injection pump, rather than the P7100 model on my 12V 1996 model.

If the lift supply pump indeed fails on my 12V with the P7100 injector pump, is there the same resulting expensive catastrophe as with the latter model 24V Cummins with the VP44 model pump? Would an early warning LED low fuel pressure light save the P7100 model pump from an expensive replacement? If so, would an LED dash-mount warning light be the best option or would an actual column post mounted fuel pressure gauge be an easier install?

Thanks for the help!

Regards,

Steve Baldridge
Edmonds, Wa.

 

just get a gauge

I think if the L/P fails on a 12 v then the truck will just quit

 

Not nearly the problem on a 12V that it is on a 24V. On a 24V the injector pump is cooled and lubed by the fuel. If the lift pump fails on a 24V, the injector pump can overheat and will eventually become damaged due to lack of fuel pressure (this is a laymens explanation - of course there are other factors that can come into play).

The P-7100 pump in your truck is essentially lubed by engine oil. So a light/guage is not mandatory - but the guage is a good idea. The guage is a good troubleshooting tool and really should be on a 12V too. If you want/need more info just ask or do a simple search.

Welcome to the site BTW.



Also, the light would not work well because a 12V makes a lot more fuel pressure than the 24V - this range is incorrect for a 12V.

 

I would suggest a quality guage to help more than a low fuel pressure light. other guages would help greatly as well if you wanted to know the vital signs of the engine.

please fill out your sig. so we know what you have.

PS welcome to the site hope you like your stay

 

yup... get a gauge.

 

FYI...the truck will still run and drive if the LP dies....mine ran for quite a while with a dead LP.

 

I am using WVO. Had 2 RAPTOR (Pure Flow/Air Dog) pumps fail. Hard to believe, but yes. Got home on a FACET round metal pump, 5.5-9.0 psi. Seems to run in that at highway speed. Is that enough pressure? The RAPTOR folks and veg guys say more like 15 psi. Thanks.