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High Pressure Fuel Pump Question

Discussion in 'LR4' started by avslash, Jul 29, 2020.

  1. avslash

    avslash Full Access Member

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    Are there 2?

    Are they the same part numbers, or different part numbers if they are 2?

    Sorry, I don't have mine in the driveway right now to crawl under and look.

    Trying to round up the parts I want to replace while the mill is out.
     
  2. Michael Gain

    Michael Gain Full Access Member

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    There are two. Was actually researching this last night. You'll want the tappets too and the service manual states to replace the high pressure fuel line when swapping out the pumps.

    Screenshot_20200728-205507.png Screenshot_20200729-182050.png Screenshot_20200729-182107.png
     
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  3. avslash

    avslash Full Access Member

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    Many thanks.
     
  4. Michael Gain

    Michael Gain Full Access Member

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    Any time. Here are the sections in the service manual to help you plan.

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  5. Michael Gain

    Michael Gain Full Access Member

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    Screenshot_20200730-080140.png Screenshot_20200730-080159.png
     
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  6. djkaosone

    djkaosone '11 LR4 HSE LUX 5.0L V8

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    I've done this. I would highly recommend depressurizing the fuel lines at the top fuel rail junction first, then proceed with the manual. You'll also want full face protection and not just eye protection from catching the escaping fuel.

    I didn't use a lift, just set it to the highest setting and rolled under it. I simply removed the sump skid and plastic side to get to it. In hind sight, if you remove the wheel well it's completely open for easy access. Also try to slide the black foam sound dampeners/covers as far away as possible or it'll be forever soaked from catching escaping fuel, like mine. Overall, it's an easy job. If I remember correctly the union fittings are 17mm.

    Good luck.
     
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  7. TrinidadLR4

    TrinidadLR4 Full Access Member

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    are there any telltale signs of high pressure fuel pumps starting to go? longer starting times, stumbling, anything like that?
     
  8. Michael Gain

    Michael Gain Full Access Member

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    I will tell you that I started researching this because of a rich bank.

    Bank one's LTFT showed over +30% which means that the ecu is adjusting for a lean condition. Since each HPFP feeds one bank, my symptoms may suggest that the passenger side HPFP is no longer sending the requisite amount of fuel to that fuel rail.

    I could be caused by other issues, but that was my reasoning.

    I'm sure some of our resident experts have a better indicator though lol

     
  9. djkaosone

    djkaosone '11 LR4 HSE LUX 5.0L V8

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    Same here. I went down this rabbit hole. Even though I cleaned it out with maf cleaner, I ended up replacing the maf sensor.
     
  10. Michael Gain

    Michael Gain Full Access Member

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    So, even though the two intakes merge at the throttle body and combine the air before entering the intake runners (ecu can't tell which air molecule is from which air intake), each MAF controls the A/F mixture for that respective bank?

    If that is true, I have more trouble shooting to do...

     

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