High Pressure Fuel Pump Question

[djkaosone]

Sounds like you found the rabbit hole. Each maf measures each bank. RH (looking from the cabin) maf measures bank1 and LH maf measures bank 2.

Also check for air leaks, it would also cause a lean reading.

 

[Aderry]

For the guys that have replaced the high pressure fuel pumps is the final torque sequence 11nm or the half turn loose?

 

[itsaguything]

I don’t think that is accurate. Due to the combined throttle body, the mafs “collectively” supply data to the ecu.
The ecu references the total air flow value supplied to the engine. These supply readings can in no way be “bank specific”.

There us a clear writeup of this in the xkr workshop manual. I’ll have a review of the LR manual to confirm.

 

[ftillier]

just from a plumbing perspective it's not possible for the MAF to be bank-specific.

 

[Tapps33]

Lesson learned when I swapped mine, pulled the alternator....it'll make life A LOT easier to get to. then start at the front and work toward the rear. I left the alternator in while I tried to get them off and it was a pain.

As for the one bank running "rich," I'd smoke check the intake first. That sounds closer to a vacuum leak than anything else....and Lord knows these things have PLENTY of places that leak!

FYI, I've been chasing the same issue on my 2010, and yes, I replaced the LPFP, then the HPFP, then the injectors on my left bank, then the plugs on my left bank....then I discovered the fuel vapor purge solenoid had failed...and when I swapped that it go A LOT better. Now, I just need to reseal my valve covers and I should be good to go.

That said, I used much of the same logic as you are when trying to diagnose.

 

[Pfunk951]

Hey Guys,

Do you think it's worthwhile to do a write up on the R&R on the High Pressure Fuel Pumps? I've seen a LOT of helpful information, but it's scattered throughout the interwebs and I've yet to see a full write up.. I ask, as I just did mine- here's the details:

1. I had the P0089 codes and went into limp mode
2. Hard start and bad idle
3. At 130k I decided to do all 3 pumps (LPFP unit in tank and 2 HPFPs)
4. It was one of the HPFPs
5. There were a LOT of techniques that could make that job a lot easier- some were touched on in this thread

Relults:

1. Truck runs better than it ever has- smoother operation, idle, etc
2. Throttle response and power have both noticeably gone up- too early to see if my MPG has recovered. I can feel it in the gas pedal, and hills that used to require a downshift to get up now use only one gear
3. Engine is a LOT quieter- I'm now hearing other noises that were muffled out-great
4. It appears that one of those pumps were setting off my bank 1 knock sensor- it cleared right after repair.

So, this is kind of a big deal with our trucks getting up there in milage..

I took pics, let me know if you want a write up so that all of us can knock this out without being fleeced by the dealership..

-MP

 

[ftillier]

People may not know they want a write up, and only appreciate it when their HPFPs need R&R. If you have time and inclination, I'd vote for a write up for posterity, while it's all fresh in your mind.

 

[16FujiDisco]

It’s always nice to have first hand documentation vs the workshop manual

 

[Pfunk951]

On it.. Maybe Atlantic British will copy us again like they did on the Transmission Pan Swap

MP

 

[itsaguything]

LOL, I like my noisy HPFP solution. It makes the tapping sound of a diesel.
I'm afraid if I change it, I'll lose the distinctive noise. ;-)

@Pfunk951 , that would be awesome.
BTW, No, the chains and glides are fine.