Engine/Transmission (1998.5 - 2002) Vp44 Question?

[DCutler]

I know that when the lift pump dies it will cause the vp44 to eventually fail, I caught the first one in time /lift pump it was getting weak, So I had it changed under warranty and now I am on my second one, how do you tell if the vp44 is going bad? do you have a check engine light come on? I can take it to a diesel place I know to have it checked the truck still runs really strong and I havent noticed anything funny, i am putting on my Fass system tonight and I will have no more worries about the problem I HOPE thanks for the input.

 

[Gary - K7GLD]

AS long as you maintain even a relatively small PSI at the input to the VP44 under all driving conditions, you are probably OK - it's the longer instances where there is NO fuel pressure - and perhaps even a vacuum if the failed LP is creating significant blockage - than can cause LP damage due to lost VP44 lubrication and cooling.

 

[MKoth]

AS long as you maintain even a relatively small PSI at the input to the VP44 under all driving conditions, you are probably OK - it's the longer instances where there is NO fuel pressure - and perhaps even a vacuum if the failed LP is creating significant blockage - than can cause LP damage due to lost VP44 lubrication and cooling.

Not true. I have had gauges on the truck since it was new, and have never seen below 5 psi WOT post filter, and my VP44 is having dead pedal and 0216 codes.

 

[gtobey]

Cummins has a light kit/pressure sender that comes on at 6 psi, but with the gauge I got from Geno's, I never let mine get below 8 psi at WOT. I added the Stanadyne 33945 back at the tank to have a pressurized and filtered supply of fuel available at the engine's lift pump. I have 16 psi at idle and 14 psi WOT now.

 

[59Turbo]

gtobey, what is a Stanadyne 33945? Do you have a link for it? Thanks

 

[gtobey]

Here's a couple of links:

http://www.stanadyne.com/new/ppt/showfile.asp?id=2344

http://www.stanadyne.com/new/ppt/showfile.asp?id=1434

The 33945 is their Fuel Manager with a 10psi regulated pump on top of the filter with a bowl at the bottom. I took pictures and am in the process of writing up my installation. I hope to have instructions available in written form soon. I mounted it to the inside of the frame rail just to the rear of transfer case above the skid plate. If you want a copy of the instructions I write up with the pics, email me or pm me and when I get them done I will send you a copy. Take care.

 

[HeavyHauler]

Not true. I have had gauges on the truck since it was new, and have never seen below 5 psi WOT post filter, and my VP44 is having dead pedal and 0216 codes.

Could it be that your LP didn't cause your injector pump problems? What Gary is referring to is strictly about lift pump failure affecting the VP44. There are many other causes for the VP44 to go bad.



I thought this was an interesting link from Blue Chip Diesel. It explains a little about injector pump failures in our trucks:



http://www.bluechipdiesel.com/injectionpumpfailures.html

 

[CCutshaw]

Good link, I for one always wondered about the electronics on the pump causing the failure.



What about the low sulfur fuel, I know they say we don't need a substitute but my 86 would stall at low speed if i didn't us it. Just a thought.

Calvin

 

[Gary - K7GLD]

Could it be that your LP didn't cause your injector pump problems? What Gary is referring to is strictly about lift pump failure affecting the VP44. There are many other causes for the VP44 to go bad.



I thought this was an interesting link from Blue Chip Diesel. It explains a little about injector pump failures in our trucks:



http://www.bluechipdiesel.com/injectionpumpfailures.html

YUP - I'm strictly talking SHORT TERM low PSI at the VP-44 - ideally, I prefer to see fuel PSI at the VP44 at no less than 10 PSI under all conditions.

 

[MKoth]

I know that my VP44 failure is not LP related, was simply trying to state that even with good FP, you can still lose a VP44.



Mine is dieing do to a TST PM3 Comp stacked with an EZ.

 

[Gary - K7GLD]

I know that my VP44 failure is not LP related, was simply trying to state that even with good FP, you can still lose a VP44.



Mine is dieing do to a TST PM3 Comp stacked with an EZ.

Actually, it can be pretty hard to accurately pinpoint exact causes for failure of a VP-44 - yours MIGHT be failing due to the add-on boxes - or quite possibly due to cruddy fuel, fuel too low in lubricity - or even VP-44 electronics failure from overheating.



I personally would be VERY hesitant to start pointing fingers at what I figured to be the cause of a specific failure, other than maybe running one for long periods of time under heavy use with a known failed LP...

 

[HeavyHauler]

Mine is dieing do to a TST PM3 Comp stacked with an EZ.

Be sure to read that article in the link that I posted. Blue Chip Diesel believes that add-on boxes cannot solely be blamed for pump failures. The only thing an add-on box will do is shorten the life-span of an already dying pump; it won't cause one to die.



Now maybe they're just saying that to cover their end if one of their customers loses a VP after installing their FMS, but I don't think so. I've talked with Chip before and he is very knowledgable about these pumps. Doesn't seem like a guy that would shoot you a load of bull.

 

[rweis]

As I interpret it the longer the fuel solenoid is held closed, the higher the probability there will be a high pressure spike in the middle of the rotor slot and flexing and galling and failure.



"The reason this happens is because the fuel solenoid is held closed longer, therefore using more length of the slot in the rotor. The slot in the rotor overlaps a hole in the distributor to allow for different timing and amounts of fuel to be delivered to the injector and when the solenoid holds the bypass solenoid closed longer, then the high “pop off” pressure is still there when the middle of the slot overlaps the hole. The middle of the slot is the weakest area and therefore deflects, interferes and seizes. "



But also clearly is the lubricity issue and the extreme close internal tolerance of the pump.



AND the durability of the circuit board.



AND the design of the pump in general.



AND, AND, AND the mentality (mine included) that because I xxx and my VP has not failed then I have the answer. I try to look at the fuel system as a SYSTEM rather than a lp pump (or FASS or RASP or XXXX), rather than banjos vs full flow fittings, rather than lubricity only, rather than prefiltered fuel with free water removed.



There is nothing I can do about the circuit board longevity. However, I can and do effect whatever I can, prefiltering, no free water, lp on frame, as close to exact feed pressure as I can (12 psi) with the bypass regulator, lubricity with Stanadyne, not tapping the pump wire so the fuel solenoid is not held closed so the "pop off " pressure is not a player (as much). Hopefully avoiding the galling with Stanadyne PF. And by dumb luck I have a 2002 (ie later model pump).



I change the things I can change, I do not change the things I can not change, and hopefully know the difference,



Bob Weis

 

[MKoth]

Actually, it can be pretty hard to accurately pinpoint exact causes for failure of a VP-44 - yours MIGHT be failing due to the add-on boxes - or quite possibly due to cruddy fuel, fuel too low in lubricity - or even VP-44 electronics failure from overheating.



I personally would be VERY hesitant to start pointing fingers at what I figured to be the cause of a specific failure, other than maybe running one for long periods of time under heavy use with a known failed LP...

I always thought that any type of fueling or timing box puts extra stress on the electrical parts of the VP, causing heat buildup, and sometimes failure.

 

[rweis]

I think that if you do not alter the VP (ie no wire tap) and you feed it properly you are then left with "normal failure" of mechanicals and circuit board.



my . 02



Bob Weis

 

[mhenon]

As I interpret it the longer the fuel solenoid is held closed, the higher the probability there will be a high pressure spike in the middle of the rotor slot and flexing and galling and failure.



"The reason this happens is because the fuel solenoid is held closed longer, therefore using more length of the slot in the rotor. The slot in the rotor overlaps a hole in the distributor to allow for different timing and amounts of fuel to be delivered to the injector and when the solenoid holds the bypass solenoid closed longer, then the high “pop off” pressure is still there when the middle of the slot overlaps the hole. The middle of the slot is the weakest area and therefore deflects, interferes and seizes. "



But also clearly is the lubricity issue and the extreme close internal tolerance of the pump.



AND the durability of the circuit board.



AND the design of the pump in general.



AND, AND, AND the mentality (mine included) that because I xxx and my VP has not failed then I have the answer. I try to look at the fuel system as a SYSTEM rather than a lp pump (or FASS or RASP or XXXX), rather than banjos vs full flow fittings, rather than lubricity only, rather than prefiltered fuel with free water removed.



There is nothing I can do about the circuit board longevity. However, I can and do effect whatever I can, prefiltering, no free water, lp on frame, as close to exact feed pressure as I can (12 psi) with the bypass regulator, lubricity with Stanadyne, not tapping the pump wire so the fuel solenoid is not held closed so the "pop off " pressure is not a player (as much). Hopefully avoiding the galling with Stanadyne PF. And by dumb luck I have a 2002 (ie later model pump).



I change the things I can change, I do not change the things I can not change, and hopefully know the difference,



Bob Weis

Bob, Excellent post! It would be nice to know what this pump could do with clean, lubed fuel coming from a reliable (steady 10psi) source. A marine application, with the tanks "above" the engine and "no" lift pump, comes to mind. Would the failure rate be greater than with any other injector pump??

If I end up keeping this truck (and that is up in the air right now) I think I'll just have a 30 gallon aux tank mounted in the truck bed. Put a FASS or Airdog right at this tank and use it as the "main" fuel supply. The OEM tank can then be the "reserve" fuel to be fed into the main tank only... . not to the engine. Then we'll see if the VP can last for any length of time.

I just can't belive DC or Cummins couldn't engineer a better fuel supply system the they did. Why do "we" have to come up with all of these after market solutions????

Still believe we all have one of the best 6 cylinder diesel engines ever put in a pick-up truck. The damn thing just needs a little fuel.

Mike

 

[hcole]

As I interpret it the longer the fuel solenoid is held closed, the higher the probability there will be a high pressure spike in the middle of the rotor slot and flexing and galling and failure.



"The reason this happens is because the fuel solenoid is held closed longer, therefore using more length of the slot in the rotor. The slot in the rotor overlaps a hole in the distributor to allow for different timing and amounts of fuel to be delivered to the injector and when the solenoid holds the bypass solenoid closed longer, then the high “pop off” pressure is still there when the middle of the slot overlaps the hole. The middle of the slot is the weakest area and therefore deflects, interferes and seizes. "



But also clearly is the lubricity issue and the extreme close internal tolerance of the pump.



AND the durability of the circuit board.



AND the design of the pump in general.



AND, AND, AND the mentality (mine included) that because I xxx and my VP has not failed then I have the answer. I try to look at the fuel system as a SYSTEM rather than a lp pump (or FASS or RASP or XXXX), rather than banjos vs full flow fittings, rather than lubricity only, rather than prefiltered fuel with free water removed.



There is nothing I can do about the circuit board longevity. However, I can and do effect whatever I can, prefiltering, no free water, lp on frame, as close to exact feed pressure as I can (12 psi) with the bypass regulator, lubricity with Stanadyne, not tapping the pump wire so the fuel solenoid is not held closed so the "pop off " pressure is not a player (as much). Hopefully avoiding the galling with Stanadyne PF. And by dumb luck I have a 2002 (ie later model pump).



I change the things I can change, I do not change the things I can not change, and hopefully know the difference,



Bob Weis

I read your post and could not agree more. I have a 2002 5- speed with 65000 mi and I'm getting the p0216 code. I've had a Geno's FP gauge post filter for over a year and never has the pressure been below 12 psi. No mods,and I have the dead pedal more and more lately. Dealer says it has to quit before he'll do anything. I am almost positive mine is in the electronics. I hate to give up my 2002 vp44 because I think it is good mechanically. I wish you could change the electronics on it. Dealer said is not possible. Been following this site for over a year and it has helped tremendously.