Motorhome Lift Pump

[Bezzer]

dbrannon79 & Will L. and everybody:
I removed my original lift pump today (this is the original that came with the new motorhome). It is a Delco #6443439. Only to find out that the max output is 5.5 psi.

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OEM / Interchange Numbers: 25117340, 6443439

DELPHI HFP921 Specifications
Amp 10
Connector Shape/Type 2 Wires/Female
Flow Rate 30 gal/hr
Fuel Type Diesel
Gasket/Seal Included No
Inlet Thread Flare
Item Grade Standard Replacement
Outlet Degrees 180
Outlet Thread Flare
Package Contents Fuel Lift Pump, Instruction Sheet
Pump Type Solenoid
System Pressure 5.5 psi
Terminal Type 2 Pins
Type/Series Solenoid
Volts 12 vDC
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So the 5.5 psi tells me that the pump is good.
Do you think that GM put the wrong lift pump on?? Wow!!
(Remember I did have the recall and they installed a new injection pump . Maybe the 5.5 psi lift pump was the problem for the recall? )

Now remember the last test I did was at the injection pump and it read 5.5 psi immediately.
So that is maxed out.
Also someone on Truck Stop stated that if my fuel pedal was "drive by electric wire" (mine is driven by electric wire) - the fuel pressure should read 8 to 14 psi.

What's going on here or make a guess ?

dbrannon79 wrote that the specs for the EP309 and EP158 - and suggested to use the EP158.
I have been carrying a new EP309 as a spare that maxes out at 8 psi and I don't think that's enough. Do you agree?

If I order the EP158 (it is supposed to give you between 8 and 14 psi). The only thing that might happen is the injection pump might feel better!! Ha Ha!

 

[MrMarty51]

FASS is a real good pump.
Delivers plenty of fuel and is never starved for PSI.
Your IP will be real happy with that.
Calling in @ak diesel driver as He has one of these on His truck.

 

[MrMarty51]

I went with the Air Dog as it also has filters on the pump.
If I had to do it over I believe I would go with the FASS system thats put together in a kit for the 6.5 diesel engine.

 

[ak diesel driver]

Yes I have the raptor. Been happy with it

 

[MrMarty51]

Yes I have the raptor. Been happy with it

Is that the same as the FASS ?
When I made the post second one before this I could not think of the name RAPTOR.

 

[Paveltolz]

Pure Flow Air Dog makes the Raptor pumps (technically AirDog Raptor) as well as the ‘AirDogII’ units.

AirDogII’s are “Flow on Fail” as are OEM lift pumps (been there, done that unfortunately). From what I’ve read, the Raptors are not. Can’t speak for FASS.

Raptor Pumps do not have their own filtration so you’ll keep the OEM FFM or can acquire an auxiliary set up to either replace or augment the factory set up.

AirDogII’s, like many of the FASS pump set ups, have water separator and filtration incorporated. AirDogII’s come in kit form and, with the new 5G series pumps, they’ve released kits for 6.5 equipped GM trucks. From what I can tell, the only real difference in the Ford, GM, Dodge kits are the frame mounting set ups.

 

[Will L.]

As to the recall- that was for the ds4 ip, not the LP (Lift pump).
Basically GM pinched pennies and only cared about the ip making it out of warranty. Only one on 25,000 would get a new LP installed. Almost no one ever actually put a pressure gauge on it after a new LP is installed so the dealerships almost never dealt with the complaints. A couple people that did- GM paid for aftermarket LP - I remember putting on Holley diesel pump they used to make in the 90’s. But those only lasted about 30,000 miles before failure.

Yes the AC Delco EP158 is the best version on the inline one- and it lasts about 8-10,000 miles usually before falling below 8psi.

So it becomes a question of cost & labor to do it multiple times vs spending more money and only doing it once. You have to do the math to see which is best choice for your situation.

If it’s a rig you know you will put 200,000 miles on- it’s worth it to get the FASS system most of the time.

Depending how much moisture is in the fuel where you drive- the Fass water separator (1 of the 2 filters with the system) is a very wise investment. Water ruins ip, injectors, and possibly pistons in certain situations. Fuel algae comes with the moisture and also ruins the same parts. Either can ruin brand new parts within a few thousand miles.

The original fuel filter/ water separator from GM was adequate for pure hydrocarbon diesel fuel which is now illegal to sell in the USA, Canada, EU, Mexico and other places. Since they started adding methanol or ethanol into the fuel- that brings in ridiculous amounts of water that the Gm filter cannot handle. So whenever a person can afford it, I suggest the FASS pump with the two filters. If in an area fuel gelling is probable- then buy their fuel heater as well for it. Then eliminate the GM one.

 

[Bezzer]

Thanks for the fast reply! As you now know I have a DS4 IP and had the recall done at 55,000 miles.....Now it has 80,000 miles.

About the LP you mentioned that GM pinched pennies and I wrote maybe the 5.5 psi LP was the reason for the recall for the failing IP.

No one will never know why there was no full recall for the 5.5 LP except GM did not care.

I ordered the EP 158 today. You said it may last 8 to 10K miles. We have finished all our long travel miles and now make short trips. At 83 the new pump should out last me.

Thanks again for all your help! Bezzer

 

[Will L.]

Just keep an eye on that fuel pressure. Be safe & have fun… not necessarily in that order.