ranman2001mods

I have a 2001 with 110k on it... What symtoms does a bad LP demonstrate
when they are bad?

Also, with the low sulfer Diesel fuel no being sold, how will that effect my
fuel systems?

thanks

DieselLady

There won't be any symptoms usually until it's too late. I highly recommend a fuel pressure gauge for your truck. You can check to see if it is providing fuel to the VP44 by cracking the fuel line from the filter to the injector pump but BEWARE. If the lift pump is shot and you open the system you probably won't be able to start the truck without replacing it as it will not prime the system again. Once you crack the line, bump the starter without starting the engine. You should hear the lift pump buzzing for about 30 secs. It should leak fuel out of where you opened the line. If it doesn't your lift pump is bad. Sometimes you can hear them and they still don't pump fuel so don't go by the sound. If it is bad and you don't replace it, it will only be a matter of time befor you lose your injector pump. It needs more fuel than it can draw on its own for lubricity and with out the lift pump suppling fuel it WILL DIE. Only a matter of time. and usually not much time either.
That being said, what makes you suspicious of the lift pump?

ranman2001mods

what makes me suspicious? just hearing all the horror stories I guess... I don't hear a lp pump coming on, but don't know exactly what I should be listening for. should one be able to hear the LP pump come on from the drivers seat with the door open? My truck runs great, ruff cold starts but I do live a 8k feet, so I just don't know.

Shovelhead

Some say low power, some hard/no start, some never see any change in the way the truck runs until the injection pump seizes.
This might not jive with what the dealer's service dept will tell you, but it's the way I run my truck.
When your full-time fuel pressure gauge* reading drops below 10 at idle, or below 8 at Wide Open Throttle, it's time to:
First, check the condition of the fuel filter.
Then:
If the filter doesn't help bring the pressures up to around 14-15 at idle and above 8 at WOT,
Install a replacement fuel pump.

Opinions may vary, but the new ULSD will mean EVERY tank that goes into my truck will get a dose of lubricity additive. (of course it gets that now)
The new stuff is already breeding stories of seized fuel injection components.....some may be true....some not...but.......

*should be every 24 valve, VP equipped owner's FIRST add-on.

Bart Timothy

The engine will run just like a fuel starved gasser if the pump is totally dead or near to dead. Starve it hard enough and the P0216 code will be immediately thrown. When the code is thown in this manner it doesn't necessarily mean death of the IP. Usually the 0216 code is an indicator of a VP44 high pressure chamber leak or stuck timing piston, which usually happens after several thousand miles of driving.

Check for the 0216 code. If it doesn't appear, you're in good shape.

Engines with a totally dead lift pump can be started by attaching a line to the test port on the return fuel line. Put the line into a container of diesel and the VP44 internal vane pump will draw in fuel, and the engine will start.

Bosch originally designed the VP44 for use without a lift pump.

Don't get to shook up about fuel pressure. Despite what you read in these forums, a few psi is all that's needed unless you going after high performance.

Low sulpher is usually associated with low lubricity. The VP44 is lubricated by the fuel flowing through it. A common failure point from a lubricity standpoint is a haed and rotor siezure. Add a lubricant to your fuel if you're concerned about it.

tudor

Anybody have anything for or against "Marvel Mystery Oil"? I use that religiously with my classic cars as a fuel additive to lubricate valve trains for engines originally dependant on leaded fuel. I have been considering adding Marvel Oil to my diesel fuel as well, but just have not been sure it was a good idea or not.. Do you think this would be good/bad for the lift pump?

DieselLady

Well not to contridict you but this is the first I have heard of this. I have seen alot of these with bad lift pumps and once you open the system the VP can't make enough vacuum to pull fuel to it. At least not without priming the pump first. As far as pressure goes, as long as you have positive pressure you should be okay, but for me I prefer to have a greater fuel flow to help carry away heat. Plus I am one for over kill. I don't like taking things to the limit.
Either way, He will need to, should, must, get a fuel pressure gauge. You will never know what or if you have pressure at all if you don't have one and I have seen plenty of failed vp44's that have failed because of a failed lift pump.

Bart Timothy

A dead lift pump is one which is not running, and the VP won't pull fuel through it. A pusher pump won't push fuel through it. A lift pump with a bad pressure relief valve will have very low pressure and possibly zero pressure, but fuel will go through it. The vast amount of lift pump failures are due to relief valve self-destruction.

If there is a restriction, the internal VP44 vane pump will pull at least 5 lbs suction when the engine is running and, hardly any at cranking, but enough to pull fuel from a line going from the scraider valve to a container of diesel. This will get an engine with a weak LP running pretty fast. Once running, the line can be removed from the schraider and the fuel will draw from the normal fuel line as usual. Of course, it's important to keep the line inserted in the fuel container while it being unscrewed from the schraider.

Unless you actually talk to the rebuilder it is conjecture to know exactly what caused a VP44 failure, unless there was a siezure. The common assumption is low fuel pressure destroys them, but I have to ask how does low pressure destroy the high pressure chamber diaphrams and o-ring seals, which is the most common VP failure point. My belief is the same hydralic dynamics which destroy LPs also destroy IPs. Many VPs die from electronic failures, and fuel pressure has nothing to do with that.

ranman2001mods

how about putting a pusher pump close to the tank in addition to the Lift pump by the fuel filter in a series? is that better?

also Fuel gauges... is there one out there that will not blow diesel fuel thoughout my cab in the event of a malfunction? Have heard this is a common problem. a friends cab smells like a diesel refinery since this happened to him.

04ctd

BD Perf (GOOGLE them) makes a pusher pump,

then you have all 3 pumps working.
a GDP is best bet, elimate LP
http://www.glacierdieselpower.com/pr...?pf_id=3920345

http://www.genosgarage.com/prodinfo.asp?number=LT_FFCPP

the lift pump is "available" from CUMMINS - it is ~$380, the GDP is $399,
the in tank MOPAR unit is $700

DieselLady

Genos Garage also has Gauges. I use the Westech as it has the sending unit and elect wires that go to the gauge. No need for extra fuel lines.
The only issue I see about running more than one fuel pump is that if the original pump fails you can't pump through it. It will create a blockage and you will be no better off. This is part of the reason it takes out the VP44 when it goes. The question I would ask is, for the sake of a few extra bucks now, why would you want to risk loosing an injector pump later. Maybe when you are far away from home. Go for the best. Ya the FASS costs a lot but so does you vp44 and a tow from the side of the road. Or, if money is that much of an issue, just fork for a good gauge so at least you can tell whats going on.

ranman2001mods

dieselady your right, at the very least I should have a gauge. I would really like to get the FASS... seems to me the best way... just can't put that kinda money into it right now, and trying to make the IP last until I can. you've helped me decide not to tandum the LP's. and just save for the FASS. after installing a gauge of course.

anyway, thanks to all for you insights... I learned alot.