New in tank transfer pump = better mpg!?!

[TPokrzywinski]

Had my transfer pump go out at 32,000 on my 04. 5. Dealer replaced the old one with a new in tank pump. My mileage on last trip 700 miles with two days in town driving in Minneapolis and average hwy speed 70mph was a legitimate 20mpg! Hand calculated. Would the new pump be the reason for the mpg increase? Prior to this 16-17 was best mileage.

 

[barleysoda]

I thought they were all in the tank on a 04. 5? Where is the stock pump located then?

 

[JOblenes]

Mine too

I had my lift pump go in mid-March and it was replaced with the in-tank pump. While I still think it is a bit early to celebrate (i. e. am not yet convinced it was not a fluke) my immediate increase in mileage was about 6% and the engine runs a whole lot smoother to boot. There was another thread on here where guys were saying they are still pulling the pressure to zero with the in-tank pump and I am thinking about getting an auxilliary pump on top of the intank pump to make sure the CP3 lasts.



Jonathan

 

[David Oxland]

Regarding the better milage :I see that they did a reflash when they changed my pump to in tank and I wonder if that made the computer read more accurately?



Also I wonder if anyone knows what type of pump the intank is ? vane geroter or other?

 

[JVantreese]

I thought they were all in the tank on a 04. 5? Where is the stock pump located then?

I have a 4. 5 with a lift pump under the hood rather then a pusher in the tank. I think the production change over to the in tank pump did not happen until the last half of the year.

 

[APersondek]

I had my LP replaced this past Jan. I too experienced better mileage right away with the new pump... . I used to get 16 around town and 18~19 highway... . after the new in tank pump went in I now get 19 around town and 23 on highway (according to overhead computer that is reset at every fill up) I always to do a hand calc too... . here is what I can not figure out……. I always used to put 32 gallons in at every fill up but now I can get 35 gallons in the tank and have about 750 mile range when running 70 mph highway



Note: I always fill to the top of the filler neck on the tank at every fill up …it used to take 10 min to get the last 4~5 gallons in the tank now it only takes 5 min or less…. its like they installed a vent mod when they changed the pump too…

 

[sag2]

Any mileage increase would be the result of the flash that is done with the new pump, not the pump itself.

 

[OHale]

Not happy hearing about these LP failures. I just crossed the 31,000 mile mark. Hopefully it will give some indication and not just die.....

 

[APersondek]

my truck had just over 45K miles on it... doing 70 MPH on a freeway interchange and it just quit... . ZERO warning..... got the truck onto the shoulder and tried to start one time... . it ran for a few seconds and died again... . and thats when i checked for codes and seen the LP was DOA... I have 7K miles on the new pump with no problem so far...

 

[JSitarski]

Had my LP take a dump on me in March, left me on the side of the road about 150 miles away from home. All dealers were closed, had it towed to a cummins dealer and they replaced the pump. If I had known how easy it was to change I would of did it in the parking lot. They charged me $583. 00, the pump was 380 and labor was 200 for a half hour of work what a joke. called DCX cust care when I got home and they told me to send the bill and explanation what happened to see if they would pay for it. It took a month and I got a check for the full amount, Thank you DCX

 

[Bekim]

Had my transfer pump go out at 32,000 on my 04. 5. Dealer replaced the old one with a new in tank pump. My mileage on last trip 700 miles with two days in town driving in Minneapolis and average hwy speed 70mph was a legitimate 20mpg! Hand calculated. Would the new pump be the reason for the mpg increase? Prior to this 16-17 was best mileage.

That's almost exactly when mine went. I might be high, but it seems to be about 1 mpg better after the pump replacement. It also might be because I don't drive as hard as before for fear of burnin' another one! The in-tank version came beginning on the '05's. According to the service manager, pushing the fuel from the tank is easier on a pump than pulling it. Anyways, if yours goes out now, they put it in the tank.
Mike
###

 

[Bekim]

Mine made a tiny hiccup on the freeway about an hour before it just quit on a surface street. I didn't think much of the hiccup then, but now, every hesitation has me wondering WHEN it WILL go again!! A fuel pressure guage will allow you to see exactly how weak these pumps are. Getting a helper pump is a very VERY good idea. Do you need to pay $650 for a FASS system is arguable on it's own thread. IMHO
Cheers
Mike
###

Not happy hearing about these LP failures. I just crossed the 31,000 mile mark. Hopefully it will give some indication and not just die.....

 

[OHale]

Mine made a tiny hiccup on the freeway about an hour before it just quit on a surface street. I didn't think much of the hiccup then, but now, every hesitation has me wondering WHEN it WILL go again!! A fuel pressure guage will allow you to see exactly how weak these pumps are. Getting a helper pump is a very VERY good idea. Do you need to pay $650 for a FASS system is arguable on it's own thread. IMHO

Cheers

Mike

###

Thanks for all the info from the posters about how LPs fail. Not good. I remember now that when my truck is on high idle there is a 'hiccup' every now and then. I wonder if its the LP getting ready to let go?



I do have a spare LP under the back seat and I need to make sure I have the nand tools to change it out. My only reluctance about the in-tank pump is that I have an American Tank aux tank in my bed. I bouight the version for my 04. 5 which (at the time) has no in-aux-tank pump. If you buy a tank from them now the aux tank has a pusher pump also for the '05 and up trucks. I suppose I could retro-fit the aux tank with a pusher. Thanks again.

 

[PGreenleaf]

I think all you people out there with our great Dodge Cummins should check your fuel tanks. Been much wrote on this subject. Elbows on top of tank, setting in concave hollows moulded into tanktop. These elbows can TAKE IN DIRT AND WATER. Which in turn wrecks the lift pump via dirty fuel!!!!!!!!!!! This has been a ongoing problem for years. Dodge claims dirty fuel not there fault. !!!!!! Some of the older models have two concaves with two open elbows open on top. If water fills the concave it submerges the elbow !!! Now I have a brand new 06 one ton cummins. I checked mine, sure enough theres the two concaves , front one the elbow is used, ( theres a line on it), at the tank rear concave there set the open elbow big as day,down in the concave. FIX, Bought two feet 1/4 in fuel line and a little inline fuel filter. Put it on the elbow, strung it down behind the tank and tank shield with filter on open end . With line on there I tryed blowing into tank. You can blow right into tank vary easely, but you CANT suck out on it. So theres a one way check valve in this elbow to keep fuel from coming out when you fill tank FULL. Nothing to stop crud from going IN. Its my opinion that right there is the cause for lift pump failures.

 

[JeepRig]

What is the code for lift pump going bad? If there is one.

 

[mattk50]

i think its p-0628---mine went out monday am at 59,000. 1 little hiccup about 10 minutes before then it just died. should get it back today-hopefully the F-150 they gave me for a rental is a p. o. s.

 

[JTCash]

Good gouge Leaf!

Thanks for the input... I'll be copying your idea.



R/



Jim

 

[JVantreese]

Anyone with a failed pump...more info please.

In talking to my tech I was hoping to get some info as to when these pumps seem to fail and what if any warning we should be looking out for. He said that there is no warning signs but thinks that changing the fuel filter regularly seems to add to a much longer life. I was wondering if I could get some feedback as to the frequency of filter changes that some of the failed pump had.



Thanks for your input.

 

[steved]

I thought they were all in the tank on a 04. 5? Where is the stock pump located then?

Early 04. 5s didn't have the in-tank pump... mine didn't...



As for your increase in mileage... most likely the old pump had been faulty for a while...



steved

 

[APersondek]

for whats its worth..... I change my fuel filter every 7500 miles (every oil change) rather its needed or not... . my pump still died @ 45K miles (see above)