Engine/Transmission (1998.5 - 2002) Do Egde Comp's Kill Vp44's?

[rweis]

My . 02



Fuel SYSTEM



Lubricity, temperature of feed fuel, correct feed psi and volume, pump tap (holding the solenoid closed longer), driving conditions.



Lubricity - fuel lubricity is the whole basis of lubricating the pump. Some tolerances internally are extremely tight measured in um. Lubrication film is essential.



Fuel is supposed to cool the pump. What temp is your "cooling" fuel. I think you will find OEM fuel is actually pretty hot. I am doing extensive experimentation with fuel cooling and can deliver OAT + 10* cooling fuel unloaded cruise. Stuck in traffic OAT + 30* cooling fuel. All that is after extensive fuel system mods. How hot does your part of the country get in OAT?



Feed fuel psi should be 13. 5 psi (Bosch). The vane pump is the key to keeping the VP44 timing, injection, and cooling functioning. Diaphram deflection is limited to . 5mm before seal damage begins.



Feed volume has to fully fill the vane pump lobe. I do not feel that the stock system design accomplishes that effectively. Hence "big line kits", AN-6 lines etc.



Pump tap. The Bosch book states the starting solenoid amperage is 18 amps, with 10 amps holding current for the closed position. Hold it closed longer, more heat in the solenoid (my thoughts). More heat adds to already temperature sensitive device.



Driving conditions. One variable very hard to get a handle on. I measure the EBC cover and know for a fact that fuel temp has a direct relationship to EBC temp and VP body temp. RPM has a direct relationship to EBC temp and VP body temp. I force OAT cooling air on my VP for engine run time and 128 minutes after engine shutdown. I have thermally insulated all fuel lines in the engine compartment. I have thermally insulated the VP. Fuel return is to the tank filler vent line. 1 active fuel cooler, 2 passive fuel coolers. Removed OEM ff. Another fuel cooling approach is in the works.



Lubricity, temperature of feed fuel, correct feed psi and volume, pump tap (holding the solenoid closed longer), driving conditions all have their contributions to VP longevity (and I just might lose mine tommorrow )



Bob Weis

 

[DieselMinded]

I had 20 PSI for 3 Mths then My Vp44 Died ,,,New VP and still 20 PSI I swapped in a diffrent Isolater and its still 20 PSI ,,,the gauge does Zero out when off so its not the isolaters .



In My Case Low Fuel Pressure was not the issue thats for certian



DM

 

[Mundgyver]

I have 166,000+ on my original VP-44 with an Edge-Comp and now stacked with a Smarty. My fuel lines have been sized up to 3/8 ID for increased volumn, so the VP cannot be starved. Fuel starvation and excessive heat kill. Thats why we run a fuel cooler just before the VP and a FASS 150 GPH set to 15 psi.

 

[DieselMinded]

What do I get some Information about a Fuel Cooler ?



i Have 1/2 inch fuel lines and the new Vulcan Swilvel Lock and two Carters and new filter every 10,000



DM

 

[SSabick]

I have just under 55,000 miles on mine, and my VP-44 has just gone out :{ . I haven't ever had a performance box on, but I do have bigger injectors. Now i have to start saving for a HRVP, and some much bigger injectors, oh yeah, and ome mods to help hold all the new power that I am wanting to lay down.

 

[Mundgyver]

This is what I use and it works great as a fuel cooler.

 

[gregdoerfler]

i must be very lucky with my vp or it is 1 in a 1,000,000, i have went 2 winters with 0 psi fp( i thought my fp gauge was not working because i could here the pump running) and this winter with a fass and good pressure now but it still is running strong. with 90,000 miles

 

[Alphacowboy]

This is what I use and it works great as a fuel cooler.

I too thought about doing this exact thing with mine, but when I asked about it months and months ago, I was told it would be a bad idea, as in cool months, it could gel the fuel... what have you found on that?

 

[rweis]

Bypass the cooler in the cooler months.



Bob Weis

 

[Turbo Tim 1]

151,000 miles, original VP, had an Edge Comp since around 42,000 miles, upgraded to the Drag version 20-30,000 miles ago and added DD II's. It's really luck of the draw. I just recently located the lift pump to the frame rail otherwise it was the stock fueling system.

 

[Graphic man]

160,000 miles on Org. VP44 wire taped for about 80,000..... still going strong..... knock on wood. . :-laf ... fuel pressure 12. 5 at idle and 14. 5-15 at WOT thanks to the RASP ..... awesome unit

 

[BManuel]

Looking at the model year of the posts who have VP44 failures, the 2002 model year seems to be the highest rate. My 2002 vp died at 54,000 with comp and wire tapped. decided to not tap the wire with replacement vp. went with bigger injectors.

Maybe since Bosch knew it was the last year for the VP44, they got rid of all the questionable units in 2002?

 

[DieselMinded]

Im went the same route as you did Got rid of the comp and going with big sticks and charger,,,, and the comment about ditching all the junk Vps laying round on the 2002 is food for thought

 

[BradyWilliams]

I am going to clarify a few things. The pump failures that we have seen with VP44 pumps associated with fueling boxes, have been for the most part agressive fueling boxes and multiple boxes or mods. I talked to one guy that tapped into a pump wire and put a toggle switch in the ash tray and connected it then to ground. He didn't know what the wire did, someone told him it was good to do. We see PSG's burnt out mostly. But once in a while we see the pumping plungers broken at the retaining clips. This is a sure sign that enough signal to make the plungers slam against the retaining clips (effective stroke) was excessive. The pump was never intended to operate in this situation. That is one of the reasons we always use new Head & Rotors in our SHOVP44 pumps. That is also why we use new PSG's (brain box)in our pumps also. We also use the very latest PSG's which is always the best built and longest lasting. Some of you call this PSG the FedEx box but we that build these pumps have known for quite a while now that it is the only one we can get from Bosch. Bosch calls the different PSG's 3 Lam. and 4 Lam. The 4Lam is the FedEx PSG that you guys refer to. We did just a few months ago receive a later part# that was new to the system, we purchased them and have had good results with them. We always look to give you the very best product available. We do have a policy of fixing your pump as inexpensive as possible when you have a Fueling Box failure, instead of selling you another exchange pump. I don't think many others are doing that. We are always trying to help our customers any way we can. Thanks, Brady 1-800-955-0476

 

[rweis]

BrettWilliams "We see PSG's burnt out mostly"



Since the VP44 uses fuel to cool itself, can I reasonably extrapolate that heat is a major cause of failure to the PSG?



I am reasonably sure that fuel cooling channels run close to the PSG mounting to help it stay cool. If I can provide cooling fuel close to OAT (outside air temperature), and can keep the PSG mounting from becomming heat soaked from the engine block after shutdown, am I on the right track?



Of course lubricity additives, clean fuel with no free water, correct input pressures (13. 5 psi) at sufficient volume (ie large enough ID lines) also play a part in the overall health of the VP44.



Bob Weis

 

[Turbo Tim 1]

With respect to the 2002 trucks, what are you seeing as the common failure? If it is the PSG, Why? The only difference I can think of under the hood is the liner. Is the lack of a noise liner allowing the PSG to have greater cycle temperatures and causing them to fail? Is the grounding different in the wiring harness? It seems that the 2002 models are failing at a greater rate, do you have any insite as to why?

 

[BradyWilliams]

The failures that we see are with regard to burnt out PSG's are of a eletrical nature with some that were short operation. The more agressive the fueling box the higher the risk of PSG and Head & Rotor damage. We too know that there is a lot of fueling boxes running on trucks every day. We have them on our trucks. My son has had to buy a VP44 himself because he had to get the most agressive program for racing. Good thing he is one of my VP44 builders. He fixed his own but still had to buy his own parts. As far as heat in the VP44 causing failures, we all know that heat affects electronics. Bosch has supplied a good cooling method in the VP, fuel enters the pump and travels under the PSG and then down to the supply pump. This helps stabalize the temp. that the PSG is operating in. One thing that I have been thinking about is the fuel heater control maybe staying on too long and in warm or hot ambient tempertures. There is no doubt that the fuel heater helps the fuel combust more completely. But in summer weather and in extended driving, does the fuel heater stay on in some vehicles? We see more fuel heaters fail than we can explain. Just a thought that I have been kicking around. A fuel heater switch on the dash? Thanks, Brady

 

[GiesJ]

Lots of great information in this thread.



I have 98. 5 and am on my 5th VP44.

1st one - completely stock around 40K

2nd one - EZ only around 60K

3rd one - Replacement for 2nd one was not correctly rebuilt

4th one - COMP and DD1s at about 80K



For the record, I would run the comp most always at level 3. Being at high altitude I would seldom play at 5x5 cause with the DD1s it was quite obnoxious.



EDIT - I am currently running untapped.

 

[rweis]

I have never seen fuel heater malfunction talked about as a possible cause of VP44 failure. What a great possibility of a failure point seldom thought of. I know I never had.



Bob Weis

 

[Gary - K7GLD]

Looking at the model year of the posts who have VP44 failures, the 2002 model year seems to be the highest rate. My 2002 vp died at 54,000 with comp and wire tapped. decided to not tap the wire with replacement vp. went with bigger injectors.

Maybe since Bosch knew it was the last year for the VP44, they got rid of all the questionable units in 2002?

Check out this thread for what might be at least a small indicator concerning VP-44 failure rates across model years:



http://turbodieselregister.com/forums/showthread.php?p=1492155#post1492155post1492155



You get twice as many later year trucks reporting, and the same failure rate per thousand, it will SEEM as though the year with the most on the road will have more failures, even if they actually have exactly the same failures per thousand...