New guy here and a high mile vp44...stock lift pump

[BIG-BLACK-DODGE]

Hi all. This is my first post. I wanted to just post on one of the other vp44 threads but wasn't able too??

Anyway, i have 2002 Ram 2500 5.9 HO 6 speed with 606,000 km's (376,000 miles) probably higher because the truck has always had bigger tires so the speedo is off a little.

bought the truck a year ago with 589,000 km's.

Truck needed alot of work. I had always heard about the VP 44 and all the problems associated with it so it was actually the Cummins Engine that I didn't want but it was the only one that was available to me at a cheap cost so i bought it.

 I started doing lots of reading on the VP 44 and try and understand how it all works. I'm a mechanic by trade but I'd really didn't know anything about the VP 44. I read a ton of information that said I needed lots of pressure to keep my  injection pump alive but this truck had the last injection pump changed at about 170,000 km so I was skeptical that the injection pump needed to have all this pressure and aftermarket fuel pumps etc when the stock lift pump had been doing the job just fine for many years. 

The original owner had his first injection pump fail at aprox 90,000 km's. They put a new pump in and once the truck was off warrant it failed again at 170,000. Owner fought with the dealer

and they put a new one in under warranty and put the lift pump in the tank.  After that he never had a problem ever again. The truck spent most of it's life here in Alberta Canada went all over BC way up to the far end of the Northwest Territories. Hot cold all kinds of towing with a heavy horse trailer all through the Canadian Rockies on regular basis and the truck didn't always have a full tank of fuel he would run it right till empty on a regular basis and then top it up .He did say he used fuel conditioner here and there but definitely not every tank. Fuel filters always came from Dodge or Napa but mostly Napa. 

 I think it probably even ran colored fuel in it from time to time because the truck was used out in the oil field.  Also the truck has had an edge juice attitude since about 200,000 km's.

It was always run on level 3 (drive)

When I first got the truck it had a bit of a hard start issue but that just ended up being bad connection at the batteries.

I was really concerned about my fuel pressure because of all talk of needing high pressure. The truck showed 8-9 psi at idle and would drop down to 1-3 psi at full throttle under load. It ran fine and it started fine. 

I decided  from all the reading I had done that this pump didn't need all kinds of crazy pressure to keep it reliable since this truck was basically driven into the ground and rat bagged it's whole life and had (at that time) almost 400,000 km's on the same injection pump.

So i ended up buying an Airtex lift pump.

 Now my fuel pressure is between 13 and 15 psi at Idol, 10-12 cruising and drops to usually no lower than 6 if i'm pulling a hill and i floor it. Drops to 6-8 then usually stays at 8-9 psi till i back out of it.

I have no idea how long this injection pump will last and when it does finally fail i know i wont be putting anything other than the stock lift pump back in. 

I'm not trying to say everyone should do the same just letting guys know that it is possible to get high millage with stock lift pumps. I have read many threads where guys running higher pressure still had lift pumps fail. 440,000 km's (273500) miles and still works great. 

But my truck is the HO so could that maybe play a roll because arent those pumps different than the non ho's? Also mine is a 6 speed so maybe the Auto trany's get driven harder than this truck did. I know the fuel filter was just filthy when i got the truck. Some dirt was laying down in the bottom of the bowl so original owner wasn't always keeping up on the maintence. 

I do have an intermittent starting issue though where the truck fires then stalls. Then fires up on second try. Seems like my fuel pressure is bleeding back. I wonder if my inj pump is finally letting go or if it's just a checkvalve somewhere? 

One other thing is it is quite a bit cooler here than some places in the usa. So that too may have played a roll too on why my injection pump has lasted this long. 

Great site by the way it will be fun reading all the tech tips. I really like this truck. A bit loud but i'm working on refining it. Can't believe how much power this thing has for having that many miles. Half bush road miles all through the mountains and half hwy miles. 

 

 

One thing i'd like to see is if those larger banjo bolt kits would help my fuel pressure drop on wide open throttle. I can't seem to find any write ups on someone doing a real world test on those things. 

Edited March 12, 2016 by BIG-BLACK-DODGE

[Me78569]

The numbers 14-20psi are happy numbers that we use.  Dodge themselves say anything under than 10 is playing with fire.

In addition to FP numbers Bosch says that our fuel systems are designed to have %30 of fuel go to the vp44 for operation and %70 of fuel go through the the vp44 and back to the tank to assist in cooling the vp44.

Look at how many %100 stock 2nd gens are on the road, no FP guage, no upgraded lift pump.  I am a firm believer that the revision that bosch did on the vp44 really helped with the issues due to fuel pressure, but why poke a hornets nest?   Stable fuel pressure cannot hurt the vp44.

 

As for the pressure drop, from my experience, the big line kit and fittings wont help your issues, your issues are due to low flow numbers.  

[dripley]

I have an 02 ho like yours. lost the 1st VP at 75K miles. Lost the OE lift pump around 140k and it was replaced with the in tank pump from Dodge. Starting issues with the VP around 180k and found out how low my pressure was, about 5 at idle and near 0 at WOT. Installed a booster pump and ran that set up until I lost the 2nd vp at 217K. I ended up swapping to an AD fuel pump around 230k. I am sitting at 367k right now and the VP seems very happy. 

Not sure why some can some can run around stock and others not. I dont believe the HO part makes much difference personally. A mystery of life I guess. Enjoy what you got.

And welcome. 

[stevens cummins]

Pressures need to be above 14 at all times to keep the VP happy any thing below that is too low. But I think one key to vps lasting with stock LP is how its drove. The VP is cooled and lubed buy the fuel, so if the LP is flowing fuel even at low pressures but you drive it hard the VP is using that fuel which provides cooling and lube but as soon as you let off the throttle  the VP isnt using the fuel  so now with the low pressures the fuel just sits there and heats up and looses its lubrication. However with a lift pump such as fast or eqivelent this what if situation is resolved because it provides enough  pressure  to keep the fuel moving  no mater what which keeps the VP happy no matter how its drove

[notlimah]

I definitely think there are some cases of 100% stock trucks that'll run a VP for 100's of thousands of miles with no problems. I've talked with a couple guys I know that are in this situation but it's hard to try and sell them on something when they're sitting there with a stock truck that's been running fine as long as it has haha

[CTcummins24V]

The first thing I did to my truck when I bought it was add an aftermarket fuel pump. It felt like a performance upgrade, so my truck was definitely not getting adequate fuel with the stock block mounted carter pump. If you want to keep your truck for a while, I'd say pony up the cash and get a quality lift pump that provides the needed pressure for vp44 cooling and lubrication, my 2 cents. Cheap insurance when a Fass or Fuel Boss is $600 and a new injection pump is $1200.

[BIG-BLACK-DODGE]

On March 12, 2016 at 7:34 PM, stevens cummins said:

Pressures need to be above 14 at all times to keep the VP happy any thing below that is too low. But I think one key to vps lasting with stock LP is how its drove. The VP is cooled and lubed buy the fuel, so if the LP is flowing fuel even at low pressures but you drive it hard the VP is using that fuel which provides cooling and lube but as soon as you let off the throttle  the VP isnt using the fuel  so now with the low pressures the fuel just sits there and heats up and looses its lubrication. However with a lift pump such as fast or eqivelent this what if situation is resolved because it provides enough  pressure  to keep the fuel moving  no mater what which keeps the VP happy no matter how its drove

I hear ya but over 400,000 km's tells me 10-12 ( and even lower at times) is sufficient or at least for this truck. 

I wonder if our Canadian fuel is better than the US Diesel is??  Or maybe our colder climate plays a role?? 

 I even heard from somebody that anything over 15 psi can actually put a hole in a disk or diaphragm that is in the injection pump I don't know if that is true.

 What I would like to know is there going to be any warning when my VP 44 finally does fail on me LOL. 

[Me78569]

There is no diapragm, in the revised pump.

 

I think the revised Bosch pumps areally much tougher than. The original design.

[BIG-BLACK-DODGE]

 And one other thing I'm curious of is, if the stock lift pump only puts out max 14-15 psi idleing, how is the fuel ever going to circulate back to the tank? My truck often sits at 13-14 psi. When i bought it the gauge read no  higher then 8 to 9 psi.  Surely if these pumps needed that much fuel pressure mine would have failed by now because who knows how long the other guy ran it like that for it was at least 150,000 km which is a lot of kilometers/miles.

 I am going to ask other guys running around my area that have as many miles on their trucks  and see how long they're injection pumps have lasted with the stock lift pumps .

[Sam53]

Hi I'm new too and recently but the 2000 ram 2500 qu/cb 4x4 24V with 184174 miles on it. when I but it all part of it was stock and she had 182746 mile (all stock and untouched) just right @ 183915 miles check engine light comes ON and by few second SHUTDOWN right in the middle of the intersection after towed her to mechanic find out stock LIFT PUMP went out and I'm lucky not lost the VP44. so all I'm saying is no body doesn't know when and were it's going to happen. just being safe is better than sorry.couple of hundreds dollars better than 1000,s.      

[Me78569]

excess fuel is still bled back to the tank even if the overflow is closed due to the way our injector system works.  We have a return feed on the back of the head that the none used injection cycle fuel travels through . 

 

Idea behind 14 psi is, we know the vp44 uses fuel to cool and lube, so why not supply it with even more fuel.  It takes approx 30 gph of fuel to power out trucks at WOT in stock form if you look at how much hp/tq our trucks make.  So why remove that cooling at lube when it needs it most?   If bosch says %30 for running and %70 for cooling then I am going to believe them.  

 

That being said after the did the 027 revision on the vp44 a lot of the common vp44 issues went %100 away.  we are seeing newer vp44's last much much longer.  

 

If it doesn't hurt to run higher fuel pressure and gph why not ya know?  

 

[stevens cummins]

20 hours ago, BIG-BLACK-DODGE said:

I hear ya but over 400,000 km's tells me 10-12 ( and even lower at times) is sufficient or at least for this truck. 

I wonder if our Canadian fuel is better than the US Diesel is??  Or maybe our colder climate plays a role?? 

 I even heard from somebody that anything over 15 psi can actually put a hole in a disk or diaphragm that is in the injection pump I don't know if that is true.

 What I would like to know is there going to be any warning when my VP 44 finally does fail on me LOL. 

You may have gotten the luck of the draw , I've seen some go 300,000 miles with the stock LP before the IP fail then change the IP and then have IP failures until installing a better fuel system its ones preference on what to do stay stock or go better, me on the other hand like to be on the safe side, and IP failures can show signs or just fail all at once

[NightHawk]

Fuel flow > Pressure but when sizing your fuel lines the pressure needs to be high enough to achieve the fuel flow required. If you search online, you can find some pipe flow calculators to determine the required pressure to achieve the desired (or needed) gph/gpm to keep the vp44 i your setup fully fueled.  Having high there needed pressure to achieve xx flow only creates issues and is no ideal for pump life either.  The vp44 is calibrated a 13.5 psi.....