Page 3 of 3 FirstFirst 123
Results 21 to 24 of 24

Thread: P0087 Fuel pres to Low Anyone have this issue?

  1. #21
    Lifetime Member
    Join Date
    Jan 2008
    Posts
    1,169

    Default

    Quote Originally Posted by 0rion View Post
    do you know what the return rate is supposed to be? I've read conflicting amounts online. I think we're down to where we have to troubleshoot these. There's just not much else left to do. You test the return rate with hoses off the injector return lines into cups and then crank (but not start) the motor for 15 seconds correct? Then measure the returns from the injectors.
    Is the end result the same as testing the balance rates at low media and high pressures?
    '07 TBSS, LS2, T42, 3SS, Black on Black on Black, Pretty much stock at the moment. EFILive will fix that

    '06 LBZ/Allison 6speed, EC, LB, 1LT, Leather
    Current Mods: EFI Live/ PTO High Idle Mod/ Factory Exhaust Brake / BD Full Bore/ TransGo Jr./ TTS Twin Lift Pumps/ MBRP 4" turbo back/ Custom air box mod/ BullyDog Outlook Monitor

    465hp/1008tq---7/25/09---Dyno Day Fast Specialties Tuning by ME

  2. #22
    Junior Member
    Join Date
    Jun 2004
    Posts
    38

    Default

    just for the sake of perhaps helping someone else down the road I'll post up the info that I have on return testing. The dealerships wants $400-$500 to do this test....they quoted my buddy $100/hr with it being a 4-5 hour job.


    Fuel Specific Gravity Testing

    Use a J 38641-B Diesel Fuel Quality Tester to measure the fuel specific gravity (API Rating). Follow the instructions on the tool to obtain the proper temperature-adjusted value. This information must be accurate for the proper diagnosis of the fuel system.

    Fuel Injector Return Flow and Fuel Pressures

    The fuel return from the fuel injectors to the tank will vary based on the API value of the fuel. Measure the Fuel API with the Diesel Fuel Quality Tester. For this reason the Fuel System Diagnosis – High Pressure Side values will vary for identifying a fuel injector or fuel pump concern. Use the following tables when referred to by the diagnostic. The first table is to be used during the initial diagnosis to identify the worst fuel injectors. After the fuel injectors that fail the first part of the test are capped off, the return flow from each uncapped fuel injector must be measured again, (not applicable to LLY). This is because the fuel system is returning less fuel to the tank, and thus the fuel pressure is higher during the retest. Failure to use the correct table may result in the replacement of good fuel injectors.

    Initial Fuel Injector Return Flow Values

    API Rating_ _ _ _ _ _ Maximum Single Fuel Injector Return Flow

    30-34 _ _ _ _ _ _ _ _ _ _ _3 ml

    35-39 _ _ _ _ _ _ _ _ _ _ _4 ml

    40-44 _ _ _ _ _ _ _ _ _ _ _5 ml



    Retesting Fuel Injector Return Flow Values

    API Rating_ _ _ _ _ _ Maximum Single Fuel Injector Return Flow

    30-34 _ _ _ _ _ _ _ _ _ _ _4 ml

    35-39 _ _ _ _ _ _ _ _ _ _ _5 ml

    40-44 _ _ _ _ _ _ _ _ _ _ _5 ml


    Fuel Injector Return Flow Test

    Note: Perform this test on both right and left bank of fuel injectors.
    1. Remove the fuel return hose from the fuel injectors of one cylinder bank. Refer to Fuel Injection Fuel Return Pipe Replacement - Left Side or Fuel Injection Fuel Return Pipe Replacement - Right Side.
    2. Clamp off the appropriate fuel return hose to prevent leakage.
    3. Install the J 45873 and J-45873-30 on the bank of fuel injectors.
    Note:
    If the engine does not start, crank the engine in 15 second intervals, with 1 minute cooling time between intervals, until fuel starts to flow into all of the graduated cylinders.
    The engine cranking speed must be more than 150 RPM during the cranking portion of this test.

    4. Start or crank the engine until fuel starts to flow into all 4 graduated cylinders.
    5. Elevate the 4 yellow hoses to retain the fuel in the hoses, and empty the 4 graduated cylinders into a suitable container and reinstall the hoses.
    6. Crank or start the engine for 15 s
    7. Measure the quantity of fuel in each of the graduated cylinders. Refer to Fuel System Specifications for the initial fuel injector return flow values.
    => If greater than the specified amount
    Note: During replacement of the injectors, inspect the inlet and outlet fittings for corrosion or contamination.
    7.1. Replace those fuel injectors that had high return flow and retest.
    7.2. Repeat the return flow test and replace any additional injectors that measure greater than the specified amount. Refer to Fuel System Specifications for the retesting fuel injector return flow values.
    => If less than the specified amount
    Refer to High Pressure Fuel Pump Test.


    Fuel Injector Return Flow Test — Enhanced


    Important: Do not perform this testing unless the vehicle has the following symptoms.
    DTC P0087 sets in memory
    DTC P0087 only sets during high ambient temperatures and while the vehicle is under a heavy load
    If the vehicle does not have the above symptoms, refer to Circuit/System Verification.
    Engine must be at operating temperature 83–87°C (181–189°F) for proper diagnosis.
    Perform this test on both the right and left bank of fuel injectors.

    1. Engine at normal operating temperature, 83–87°C (181–189°F).
    2. Remove the fuel return hose from the fuel injectors of one cylinder bank. Refer to Fuel Injection Fuel Return Pipe Replacement - Left Side or Fuel Injection Fuel Return Pipe Replacement - Right Side.
    3. Clamp off the appropriate fuel return hose to prevent leakage.
    4. Install the J 45873 and J-45873-30 on the bank of fuel injectors.
    5. Place the 4 yellow hoses into a suitable container.
    6.Engine running until fuel flows from all 4 yellow hoses.
    7. Engine at idle, command the fuel rail pressure to 120 MPa (17,400 psi) with a scan tool.
    Note: It may be necessary to exit command after each cylinder to ensure commanded state does not time out.
    8. With the rail pressure commanded to 120 MPa (17,400 psi), place each of the 4 yellow hoses one at a time into the 4 graduated cylinders for 30 s each.
    9. Ignition OFF.
    10. Measure and record the fuel return volume in each of the graduated cylinders.
    11. Repeat Steps 1–9 on the opposite bank of injectors.
    12. Add together the recorded injector return flow volumes of all 8 fuel injectors to determine the total injector return flow volume.
    13. Verify the total injector return flow volume is greater than 144 ml
    => If the total injector return flow volume is less than 144 ml
    Refer to High Pressure Pump Test.
    => If the total injector return flow volume is 144 ml or greater
    Replace any injector with an individual injector return flow volume of 18 ml or greater.

    High Pressure Fuel Pump Test

    1. Attempt to start the engine.
    => Engine cranks but does not start
    Replace the high pressure fuel injection pump
    => The engine starts and runs...continue to step 2
    2. Engine at idle.
    3. Command the fuel pressure control to 145 MPa (21,030 psi) with a scan tool.
    4. Verify the Actual Fuel Rail Pressure is the same as the commanded fuel rail pressure.
    => If the engine does not start or the actual fuel rail pressure is less than 145 MPa (21,030 psi)
    Replace the high pressure fuel injection pump.
    => The Actual Fuel Rail Pressure is 145 MPa (21,030 psi)...continue to step 5.
    5. Engine speed above 1000 RPM.
    6. Command the fuel pressure control to 180 MPa (26,106 psi) with a scan tool.
    7. Verify the Actual Fuel Rail Pressure is the same as the commanded fuel rail pressure.
    => If the actual fuel rail pressure is less than 180 MPa (26,106 psi)
    Replace the high pressure fuel injection pump.
    =>The Actual Fuel Rail Pressure is 180 MPa (26,106 psi)...continue to step 8.
    8. All OK

  3. #23
    Junior Member
    Join Date
    Jun 2004
    Posts
    38

    Default

    we haven't really figured out what we're going to do yet....the test doesn't seem like something that's completely beyond me. I've just never done it and it seems pretty intimidating. I would love to swap my injectors into his truck to and find it that way but not sure how I feel about using $3k worth of my injectors for a trouble shooting project.

  4. #24
    New Member
    Join Date
    Nov 2017
    Posts
    1

    Default

    Can I do this with just the EFI Live or do I need to buy the programmer license or flashscan?
    Driving me crazy with this code and limp. About to sell it if I cant resolve.

    Thanks
    Jeff

Page 3 of 3 FirstFirst 123

Similar Threads

  1. Low fuel rail code P0087
    By Tarkstoys in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 9
    Last Post: August 6th, 2011, 06:15 AM
  2. Strange fuel issue
    By Forcefedperformance in forum Forced Induction and Nitrous Oxide (N20)
    Replies: 3
    Last Post: August 24th, 2009, 06:13 PM
  3. Fuel cut at 1000rpm Issue
    By Scoota in forum RoadRunner Real-Time PCM Emulator
    Replies: 0
    Last Post: August 29th, 2008, 09:57 AM
  4. Fuel injection issue
    By odd boy in forum General (Petrol, Gas, Ethanol)
    Replies: 8
    Last Post: June 2nd, 2008, 01:50 AM
  5. Fuel Issue
    By Beer99C5 in forum Gen III V8 Specific
    Replies: 3
    Last Post: May 19th, 2007, 10:08 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •