Engine/Transmission (1998.5 - 2002) Dealer installed an in tank lift pump.

[NevadaBackroader]

Just had my third VP44 installed under warranty at 80K. It had been sick for about 20K. I waited until it set the 216 code at idle right after start up. I had lots of dead pedal in all sorts of driving conditions and white smoke, no power at start up and while going down hill. The dealer installed an in tank transfer pump that flows almost double the old lift pump but still uses the old fuel lines and banjo fittings. The mechanic told me it would show about half the normal pressure on my gauge. More flow, less pressure in the same lines. I don't understand. I also had them flush the fuel system with detergent.

Now for the good news. I just put 500 miles on it in 95 degree weather pulling 9000# with no problems. Fuel pressure is 11 at idle and 5 at full load.

Any body else have experience with the new in tank lift pumps from Dodge?

 

[Sea01Cummer]

Is this covered by the 5 yr 100000 mile engine warranty or a extended warranty that you bought. I will be picking up a 01 that i bought today, i would like to quiz them about the new lift pump. The truck i bought is still under warranty till march.



Thanks Steve

 

[Supermod56]

From what I have been reading, I am not impressed at all with the in-tank retrofit. Those pressures are too low, you don't want to be under 9 at WOT. And how in the heck can it flow double with the stock banjos and lines??? Those holes are pretty small!!!! If anything they ought to put it on the frame near the tank, that is one thing that Chevy got right. Glad I just ordered the RASP!!!!



Tom

 

[Jeepmullet]

From what I have been reading, I am not impressed at all with the in-tank retrofit. Those pressures are too low, you don't want to be under 9 at WOT. And how in the heck can it flow double with the stock banjos and lines??? Those holes are pretty small!!!! If anything they ought to put it on the frame near the tank, that is one thing that Chevy got right. Glad I just ordered the RASP!!!!



Tom

I'm sure you forgot to send it to my house. :-{} :-laf

 

[Supermod56]

OOPS!!! Should have gotten your address!!!! :-laf

 

[NevadaBackroader]

It's covered by the 100K engine warranty. I agree that the pressures are low but the performance is there. I'm going to run it hard for the next 19K and see if it needs replacing just before the warranty expires.

 

[JeffWhite]

pressure???

I just had mine swapped under warranty to the in-tank, am not seeing

near the pressures you are, me and several others can pull it to 0 or

at least nearly so at WOT - what gives? My engine is completely stock

'cept the BHAF and muffler eliminator.

 

[Supermod56]

I sure hope Dodge has plenty of VP-44's laying around for the in-tank pump conversions!!! 0 psi will kill it off in short order, no matter what the dealer says.

 

[NevadaBackroader]

Well, the mechanic at the dealer was pretty knowledgable. He said the VP44 doesn't care how much pressure it gets. It just wants volume. He tested my in tank pump at 70 (ounces/minute? I didn't get the units) and he tested my old lift pump at 44. I didn't think to ask if this was on the bench or at the injector pump. The fuel pressure doesn't drop as fast when I hit the throttle, so maybe he has something there. I also have the Stage II AFE filter and a diesel 4" straight through muffler with 4" pipe starting at the resonator outlet.

 

[Supermod56]

True on the volume, although I can't see how it can go through those tiny holes in the stock banjo bolts. I guess time will tell on this new pump!!!



Tom

 

[nps]

It doesn't seem to be physically possible to increase flow while also reducing pressure to the VP44 unless the restriction building the pressure is in the return line inside of the intank fuel module, and the intank module reduces this restriction.

 

[Supermod56]

It doesn't seem to be physically possible to increase flow while also reducing pressure to the VP44 unless the restriction building the pressure is in the return line inside of the intank fuel module, and the intank module reduces this restriction.

Thanks for reminding me to fix that lousy-design module while I'm at it!!

 

[NevadaBackroader]

What restriction are you talking about? Was there a reduced opening at the fuel return in the tank? By the way, an easy way to help reduce the fuel temperature in the summer is to make sure you keep the fuel tank more than half full.

 

[nps]

What restriction are you talking about? Was there a reduced opening at the fuel return in the tank? By the way, an easy way to help reduce the fuel temperature in the summer is to make sure you keep the fuel tank more than half full.

I'm not familiar with the design of the fuel module inside the tank. However, if what the dealer is saying is true (more flow volume with less pressure as a result of the new intank LP and module), then it can only be possible if the old return line had a restriction in it that was eliminated by replacing the old fuel module with the new intank module.



The reason I say this is that the old LP is next to the VP44. The only thing between it and the VP is the filter. Many members have pre and post filter pressure readings, so the filter as a restriction is a known entity.



With the new intank pump kit, the only things that change in the fuel flow system are the intank module itself, and the old LP is bypassed. Therefore, how can you get more volume with less pressure? The answer can't be because the old LP is bypassed - it was responsible for creating the pressure in the first place.



So the answer must be a restiction in the intank module was eliminated with the redesign. Or the dealer is telling a story to cover for the low fuel pressure with the new design (we know a dealer wouldn't do this huh ).



To verify, one would need to do a volume test. The old minimum was 44 ounces on the 25 second LP run after bumping the starter. It has been posted that new LPs generally did about 70 ounces. It would be interesting to see how much volume the new intank pump flowed into a bucket.



About the fuel temp decreasing with more than a half tank - there is speculation that since the fuel returned to the tank is dumped into the fuel module, it is therefore more likely to be returned to the VP instead of mixing in the tank, thereby heating the return fuel even more on the next trip round. So keeping at least a half tank should help - but may not help as much as expected. Another reason why Supermod56 wants to fix the module.

 

[NevadaBackroader]

Good answer. A restriction will increase pressure and reduce volume. Thanks for the reply.