lift pump replacement @ warranty

[rcaldwel]

dodge service-lift pump

Thats what I did. after this last weekend installing a FP gauge, I made an appointment with local dodge to check out FP. My reading at idle was a little less than 8 PSI. They checked it out this morning and said not a problem. We'll replace it under warranty due to it not meeting minimum PSI of 10 at idle. No questions, hassle, just unexpected good service.



bob caldwell

 

[Hemiville]

pump pressure?

Everyone seems to agree that even if the lift pump fails, the vp44 will still get you home? I wonder what the consequences of tooo much pressure are. Maybe it is a good thing to have only 4 or 5 or six pounds of lift pressure, thereby limiting the damage to the 44, if it can , in fact "pull" the fuel enough to get you home??

 

[Steve St.Laurent]

Hemiville, I have to disagree with you. I believe that most would agree that if the lift pump FAILS you'll most likely be dead on the side of the road and will most likely damage your VP44 pump. If it is failING and the pressures are low you can drive on it for a little while. The STAR hotline is D/C's troubleshooting people and the ones that can deny or approve warranty service - they are on the front lines on these kinds of issues. That information I gave above on an absolute minimum of 8 psi at WOT is from the STAR hotline as passed to us from a member that works at a dealership. I am trying to verify through a TDR contact at STAR for us. In my research on a lift pump solution for myself (adding a low pressure pusher pump in series with the factory lift pump) I talked with engineers at both D/C and at Cummins that work on the ISB regarding what fuel pressures would be safe with the VP44. Both of them told me that the more the better up to a point, and that 20 psi (my setup hits a peak of 19 psi at idle) is totally safe. I went through 4 stock lift pumps in 60,000 miles and now have 40,000 miles on my current setup with no failure. The VP44 does have a pump in it that can draw fuel - but it has to be fed sufficiently or you are cutting into the amount of fuel available for lubricating and cooling. Remember that a minimum of 70% of the fuel fed to the Vp44 is supposed to be returned to the tank for cooling and lube. That means that theoretically you could lose 70% of the fuel flow and still have full fueling to the engine - but ZERO for cooling and lube. Here's the statement from above again:

Briar, I would like to step in here and tell all of you with the 24 Valve that according to DC the lowest you want to see at the injection pump is 8PSI at WOT under any conditions. They have upped the low pressure limit because of injection pump failures. Under load the pump is not getting enough fuel through it to lubricate it and if the pump clearances are a little tight you will have a failure if run at a lower fuel pressure over a period of time. Just a concern all of you might want to think about.



David

That's from the STAR hotline to a dealer saying that they need to replace the lift pump if fuel pressure ever falls below 8 psi because of injection pump failures that they've seen. If anyone would have that answer it would be the STAR hotline. Rick, AFAIK this information hasn't been passed out as a TSB or anything - but from the sounds of the above post if they talk with the STAR hotline they'll get it. I am trying to verify the information.



-Steve



P. S. Update - I have talked with other sources and the information is accurate.

 

[Cliffman]

Quote:

P. S. Update - I have talked with other sources and the information is accurate.



This is not good . I can get my fuel pressure down to about 5-6 PSI at WOT I thought I was doing good with 12 PSI at idle, 12-11 PSI at cruising speeds and 5-6 PSI that WOT. although, I have to get on it pretty hard to get it down to 5 PSI. Looks like I'll be adding a helper pump here in the near future :{ .

 

[Steve Campbell]

Thank you Steve St.

I am very glad to hear the #'s out of STAR. I had subscribed to the "anything above zero" pressure in the worst case scenario was adequate. I guess my money was not where my mouth was because 8# is the lowest I can pull my system at anyconfiguration of weight,HP, speed, etc.

 

[1tuffram]

What is "STAR"

What does "STAR" stand for, is it an abbreviation? What is STAR's purpose and function. Can we contact STAR or is it only dealers have the number to talk to them?

 

[Cliffman]

8 PSI

Hey Steve St. Laurent,



Set my SPA fuel pressure gauge for 8 PSI. With the comp box on setting 1 I'll get a quick flash of the red light at WOT. Do you think this is enough to damage the VP44?

 

[Steve St.Laurent]

1tuffram, dealers only - don't know what it stands for. As I said above it's the arm that deals with warranty issues. Remember when lift pumps were on restriction? At that time the dealers had to call them and they would troubleshoot it over the phone and authorize a lift pump to go out to the dealer. Also the place dealers call if they are having trouble fixing a problem.



Cliffman - couldn't tell ya, I'm not an engineer. I'm just repeating something that was posted on here from a member that works at a dealer and that I've verified through other sources. Lot's of people have run around (myself included) on lower pressures than that for long periods of time. Based on what was posted my VP44 must be on the way loose side of the specs because I ran around on a dead lift pump for at least 20,000 miles before I put a gauge on.



-Steve

 

[MCummings]

Originally posted by Steve St. Laurent

Based on what was posted my VP44 must be on the way loose side of the specs because I ran around on a dead lift pump for at least 20,000 miles before I put a gauge on.



-Steve

Steve, not to second guess you, but I am a little bit gullable, (okay, Alot), but my Dad isn't.

I took your saying "20,000 miles with a dead lift pump and didn't know it" saying and said, Wow, I gotta be carefull,, my Dad took the same saying and said,, "How did he know it was out for 20,000 miles?, When did he know it went out, How could he tell, and why didn't he do something about it 20,000 miles before?"



So Steve, not to second guess ya or anything, but Now I'm wonderin', How did you know it was bad for atleast 20K ?



BTW, I ordered a dual pump (low press. pump by tank, high press. pump in stock location) from Doug and Andy, my Lift pump is dying fast, there setup (with new lines and fittings) should be here thursday)



Thanks,

Merrick Cummings Jr



P. S. Fuel Pressures are 12-14 @ idle 9-10PSI cruising, 6-3 PSI WOT (PE COMP + DD1's) or, A Vaccum (-0PSI) when the pump decides to quit, which happens at random. (truck still runs, I just turn the COMP off)

 

[Steve St.Laurent]

Here's what happened Merrick. I bought my truck used with 28,000 miles on it - my first diesel. I immediately bought the service manual as I do with all my vehicles. Reading through the maintenance stuff I was checking out what it took to change a fuel filter. Read their warnings about priming the fuel system and that if you can't get it started by priming the low pressure side that you'll have to crack injector lines and wear double leather gloves or else risk injecting diesel fuel into your bloodstream, etc, etc (which I now know is largely BS). So based on that information I decided to have a prime-loc remote fuel filter kit installed on my truck so I wouldn't have to worry about losing the prime. I took it to Cummins Michigan for the install of the kit. After installing the kit it took the mechanic an hour and a half to get my engine running again - which I now know means a bad lift pump that can't prime the system. Since I had the prime-loc system on there (which I have since removed because of restrictions causing low fuel pressures) I changed my filter twice after that and didn't have a problem getting it restarted because the check valves on the prime-loc prevented the loss of prime. After seeing the recall on 99-00 trucks (which didn't include mine) I decided to put a fuel pressure gauge on my truck because based on what had happened I thought my lift pump might be bad. What I found was that the lift pump was only producing 6 psi at idle and the second I started rolling it was at 0 (pulling vacuum I'm quite sure - but my gauge doesn't register vacuum). I'm assuming that since it took the mechanic an hour and a half (and a TON of cranking on the starter) to get the engine refired after a fuel filter change at 30,000 miles that it was bad then, 20,000 miles later was when I put the fuel pressure gauge on the truck. So basically, based on what I had read I didn't know that it wasn't normal for it to be that hard to get the engine going after a fuel filter change (I left that shop thinking WHEW, sure glad I brought it to them, I would have given up).



-Steve

 

[mdlowry]

Seeing the rest of the replies on this thread, I now suspect that my lift pump may be boarderline. Does anyone have the part number for the most recent rev of the lift pump?

I know that some people here have changed to different pumps and/or added a second pump. Are there kits for this, and who sells them? I think I'll take a look at my other options.

 

[Steve St.Laurent]

The latest rev lift pump # is 3990105 from Cummins. Don't buy it from Dodge - it'll be about $350, from cummins about $150. Enterprise Engine performance www.enterpriseengine.com sells a pusher pump kit with everything you need to hook it up except for the electrical wire to run back to the pump.

 

[MCummings]

Originally posted by Steve St. Laurent

Here's what happened Merrick...



-Steve

Thanks, Steve, exactly what I was looking for. It's guys like you that keep the TDR proud.



Merrick Cummings Jr