Engine/Transmission (1998.5 - 2002) Pusher lift pump installed - lift pump demon is slain (hopefully)

[apkole]

same truck, new power

Steve, I towed my TT up to Silver Lake last (wed) evening. Woohooo! That new lift pump makes a big difference. Nice that the engine isn't being defueled when I want it to work in the hills. I believe you're correct in calling for the fuel pressure guages for these trucks. I caught up to a friend this last weekend who has a '99 5 speed. He collects and hauls alot of old iron, (tractors, windmills, etc. ). He was not surprised to hear of the lift pump issue. He commented that he had been through four of them. He's at around 80K for mileage. Said forget the warranty, he doesn't have time to give up the truck for the dealer to play with for a day. Question: How does starving the injection pump for fuel impact the longevity of same??



Oh yeah, and I got sunburned teeth again driving past the dunes at sunset. I jes hate it when that happens!!

 

[Cliffman]

Another one bites the dust

Took a 2 week vacation to Colorado and the lift pump died while fueling up at a gas station 40,000. Glad I had a gauge on it and a spare lift pump in the tool box Took about 2 hours to R&R.

 

[Steve St.Laurent]

apkole, starving the VP44 injection pump for fuel will drastically affect it's lifespan. The pump is cooled and lubricated by fuel, the P7100 pump on the 12v trucks is lubricated by engine oil.



For you guys that are installing/have installed/thinking about it I have noticed one item with mine and it was something that I halfway expected so I was looking for it. If you turn the ignition on and try to start the engine while the lift pumps are operating (putting out 20 psi in my case) it will take a little longer than normal to fire over, about a second and a half of cranking tops (because anything over 7 psi can cause a hard to start problem), I am just waiting until about a second after the lift pumps shut down (4-6 seconds) and then crank it and it fires instantly. I think the reason for the problem is that it takes the system longer to bleed down from 20 to 7 than it does from 16 to 7. Also I think that if the relay is fired already then the low voltage coming from the ECM to the lift pump is probably enough voltage to keep the relay fired thus keeping it running and keeping the fuel pressure higher. When the lift pump shuts down and you then crank then it's the low voltage and I don't think the relay gets fired at the low voltage so then you are running on just the engine pump. What are you guys seeing?



-Steve

 

[apkole]

starting with good lift pump

Steve, that mirrors my experience. My 91 picks right off when starting. I always found it a little curious that I had to stay on the starter longer to get the 99 to start. You've most likely hit the nail on the head (again). Don'tcha just hate it when you're right? Happens infrequently with me.



Also. since I don't know how long we ran with the de-fueling situation, any hints on what to look for with injection pump. Is this a go-no go thing or will I see a gradual dropoff in performance?



Thanks



Andy

 

[stseeber]

Steve: I printed out all your install directions and have new pump from cummins west. Just ordered pusher kit from Enterprise and will do the whole thing at same time. Why is my truck still running so well with no FP? Anyway I depend on my stock truck to make a living and cannot afford any breakdowns. This will be third pump 1st pump died at 58k and I am now at 113k with 0 pressure at idle. Always starts easy, and never falters on hills. I havent towed a load since checking pressure and will wait until after pusher is installed. Thanks to you and all the other concerned Dodge owners for the great info and incite about these vehicles. Steve in northern Ca.

 

[fj40charles]

Anyone try the kit from Piers? I just ordered one from him and wanted to know if it is any different from Enterprise or JRE.



Thanks,

Charles

 

[ARARAR]

new pusher

You said the pressure gauge is always pegged @16. Does adding a pusher increase the pressure x/potentially? Are you actually @ 22psi? Is this a little much for the injector pump?

 

[Steve St.Laurent]

ststeeber - what you have to keep in mind is that a minimum of 70% of the fuel delivered to the pump is supposed to be returned to the tank for cooling and lubrication. How I take that is that you could have a significant loss in flow and still have ok performance, you've just cut WAY down on the amount of fuel being delivered to the pump for lubrication and cooling. I rigged up a 5 gallon fuel jug as a temporary tank several months ago because I needed to remove my fuel tank and deliver the truck for a repair. In less than 10 minutes of running the fuel had heated up from 55 degrees (ambient temp) to 105 degrees with sedate driving and my fueling box turned off.



arar - I'm hitting a peak of 20 psi, 16 psi shown on the gauge plus the resistors I'm running that take approximately 4 psi off of the sender's reading to the gauge (verified with a mechanical gauge). I've posted this a number of times and thought I had in this post but I guess not. When I installed this system I talked with both a Cummins and a Dodge engineer that are responsible for the 24v engine in our trucks and both of them said that 22 psi was no problem for the pump at all and that the higher the pressure the better. With the one exception that anything above 7 psi while cranking could cause a hard start condition. As said above I simply wait until the pumps stop running before I crank the engine (approx 2-3 seconds) and I don't have any hard start problems. I know of a couple of vendors that have tested with up to 50 psi of fuel pressure and didn't blow anything - at least one of them for 30 minutes+ on the dyno - they didn't however see any performance increase. I'm at about 45,000 miles on the pusher pump setup with no failures or reduced pressures at this point.

 

[JTroiano]

I've had 22psi's for three days and no problems. It runs good. I just wait for my heater grid to turn off and it fires perfect. It doesn't sound like you guys wait? Waiting for new clutch so I can feel the power.

Jon T

 

[Cummins Cowboy]

I got to thinking about how it seems like some have more lift pump probs than others. And it has also been mentioned about how much the fuel was heating up, when steve did the test with the gas can. So does it stand to reason that it would be better for the stock lift pump and the vp44 for that matter to try and not run the fuel tank down so low, refuel at say 1/3 of a tank remaining??

 

[JTroiano]

How about running the fuel through a small trans. cooler??

Jon T

 

[lsenus]

That's what I love about this club. There are so many creative ideas. A fuel "cool can" could also be used.

 

[TomGolden]

Originally posted by fj40charles

Anyone try the kit from Piers? I just ordered one from him and wanted to know if it is any different from Enterprise or JRE.



Thanks,

Charles

Charles,



When you get the Piers kit, please let us know what is in it. The pump, mounting brackets/bolts, relay, wiring harnes,... ... I also would like to know what differences there are between this kit and the Enterprise Engine kit, which I was going to order tomorrow. I didn't know Piers had such a kit, so you definitely have my interest.



Thanks,

Tom

 

[fj40charles]

Tom,



I talked to Piers and he said he uses the same 7 PSI Carter pusher pump as the enterprise. It is supposed to come with a wiring harness, relay, and fuel hose.



I'll let you know when I get it.



Thanks,

Charles

 

[Gary - K7GLD]

At this point, I am fully aware of the adviseability of installation of a GOOD pusher pump to assist the stocker - but also haven't a CLUE as to which pump is best to install!



According to posters here and in related threads, a significant number of the added pumps themselves fail - as does the original stock one on ocassion even after the pusher is installed...



Meanwhile, the one used as original equipment has been heavily upgraded over a period of time, and failures seem to have decreased - so *I* am wondering if simply buying and installing the "latest and greatest" as used by Dodge/Cummins for a pusher isn't as good as any - other than it's higher pressure than the 7 lbs or so some seem to recommend in pusher service...



If I *do* use the latest improved stock LP as a pusher, wonder if anyone has found a cost-saving source? Or does it put out too much pressure?

 

[Cliffman]

Enterprise Helper Pump

I've been running the Enterprise Helper Pump for at least 10k miles and I have a total of 40k on the 2nd OEM lift pump. Both pumps are hangen in there at 20 psi. First pump went out at 40k. I can't help but wander if maybe the reason for some pumps lasting long than others is the climant we live in. The warmer the fuel the thinner, and just maybe it's easier for the pump to do it's job

 

[JTroiano]

If you use a stock pump as a pusher and the one in the truck is still putting out 15 psi you will have a total of 30 psi together. I put the 15-18psi Carter P1601HP pump as the pusher and it went to 30psi. I then got the P1600HP (7psi) and used that as the pusher with the P1601HP as the main pump and now I see 22-23psi. It is supper easy to wire. Hope this helps.

Jon T

 

[TomGolden]

I'm also wondering if a 7 PSI helper pump is really enough. I am not a fluid flow expert, but I seriously question the notion that two pumps in series like these would have their pressures simply add together. Meaning I don't really buy the notion that if your standard lift pump is putting out 15 PSI, and then you install a 7PSI pump back by the tank, that your total pressure now goes up to 15 + 7 = 22 PSI. Maybe it really does work that way, but I just don't quite believe it's that easy... .....



With my recent problem of the mysterious "defueling" when under WOT acceleration and I see ~8 PSI on my fuel pressure gauge when this defueling occurs, I would like to come up with a pump combination that will absolutely never go below 10 - 12 PSI under *any* circumstances.



So, for any of you guys that are running the standard LP in stock location and one of the lower PSI helper pumps back by the tank (Cliffman, Steve St. L,... . ) would you be so kind as to let me/us know what you see for fuel pressure at idle, highway cruising speeds, mild and WOT accelerations? I'd love to know if a 7 PSI helper pump really can keep fuel pressure in the double digits at all times.



Thanks all,

Tom

 

[Steve St.Laurent]

My readings are:

20 psi at idle

between 18-20 psi at cruise depending on outside temp and fuel temp

never below 16 psi at WOT with the Powermax on 9 and 275 injectors



That's with 45,000 miles on the two pumps and are the same pressures I've seen since I installed them.

 

[Riflesmith]

Tom,

I just replaced my lift pump with the latest revision pump. I have had a 7 psi pusher pump on my truck for a year now. With my original lift pump(and pusher pump), I was seeing 16psi idle, 13psi at 70mph cruise, and around 5psi WOT. I bypassed my pusher pump on Monday of this week and checked my lift pump. It was putting out 8psi at idle and I could get it down to 6psi just by goosing the throttle in the driveway.



I purchased and installed the new pump on Tuesday. Fuel pressure is now above 16psi under all engine speeds and loads. Can't give you exact numbers, my gauge pegs above 16psi. One thing I do know, the truck runs excellent and I have peace of mind knowing the VP44 is getting all the fuel it needs to run the engine and stay cool.



A sidenote, I took the bad lift pump apart and could not see anything mechanically wrong with it. I can't explain the lackluster performance. It is mechanically sound enough that I am going to keep it in the truck so I can have a spare in case I need it.