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MBE 900 LACKOFPOWER

There are several causes for lack of power. These probable causes are: ‪

  • Aerated Fuel
  • High Fuel Pressure
  • High Fuel Temperature Return
  • Restricted Air Cleaner Element
  • Restricted or Cracked Charge Air Cooler or Leaking Intake Manifold
  • Faulty Exhaust System
  • High Inlet Air Temperature
  • Incorrect Camshaft Timing

Troubleshooting Procedure for Aerated Fuel

To determine if aerated fuel is causing lack of power, perform the following steps: ‪

  1. Test for aerated fuel.
  2. Disconnect the fuel line return hose from the fitting located at the fuel tank; refer to OEMguidelines.
  3. Place the open end of the fuel line into a suitable container.
  4. Start and run the engine.
  5. Operate the engine at 1000 rpm.
  6. Visually check to see if air bubbles are rising to the surface of the fuel that collects within the container.
    1. If air bubbles are not present, shut down the engine, check for high fuel pressure; refer to section .
    2. If air bubbles are present, shut down the engine; refer to section .

Aerated Fuel Resolution

Perform the following steps to resolve aerated fuel condition: ‪

  1. Tighten all fuel line connections between fuel tank and fuel pump; refer to OEMguidelines.
  2. Visually inspect all fuel lines between fuel tank and fuel pump for leaks.
  3. Repair damaged components as required; refer to OEMguidelines.
  4. Verify aerated fuel resolution; refer to section .
Test the Engine with Aerated Fuel Resolution

Perform the following steps to determine if aerated fuel resolution has resolved lack of power condition: ‪

  1. Start and run the engine.
  2. Run the engine at idle with a no-load condition for approximately five minutes, allowing the engine coolant to reach normal operating range.
  3. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check for high fuel pressure; refer to section .

Troubleshooting Procedure for High Fuel Pressure

To determine if high fuel pressure is causing a lack of power, perform the following steps: ‪

  1. Remove the fuel temperature sensor. See Figure 42903 .

    1. Fuel Temperature Sensor ‪

    2. Engine Wiring Harness ‪

    Disconnecting the Sensor

  2. Install the adaptor J-46377 , banjo fitting, and high pressure line J-46372 . See Figure 42904 .

    1. Banjo Fitting ‪

    2. Solenoid Unit Pump ‪

    Connecting the Adaptor

  3. Attach a calibrated gauge J-46378 capable of reading 0 - 100 psi., to the high-pressure fuel line J-46372 , leading to the tee fitting. See Figure 42902 .

    1. Engine Trim Panel ‪

    3. Fuel Temperature Sensor ‪

    2. Engine Wiring Harness ‪

    Attaching the Calibrated Gauge

  4. Start and run the engine to the speeds listed in Table and record the fuel pressure.

    Engine Speed, rpm. ‪

    Fuel Pressure, kPa (psi) ‪

    600-650 ‪

    430 (62) ‪

    2500 ‪

    400-650 (58-94) ‪

    Fuel Pressure at Various Speeds
  5. Shut down the engine.
  6. Remove the adaptor, banjo fitting, high pressure line, and high pressure gauge.
  7. Reinstall the fuel temperature sensor.
  8. Analyze the measure fuel pressure readings.
    1. If the fuel pressure is within specifications listed in Table , check for high fuel temperature return; refer to section .
    2. If the fuel pressure is greater than specifications listed in Table , refer to section .

Metering Valve Replacement

Perform the following steps to replace the metering valve. ‪

  1. Remove the metering valve from the fuel return line.
  2. Install a new metering valve. See Figure 44018 .

    1. Unit Pump ‪

    4. Check (Overflow) Valve ‪

    2. Bypass to Fuel Return Port ‪

    5. Metering Valve ‪

    3. Nozzle Holder ‪

    Metering Valve Location

  3. Verify metering valve replacement; refer to section .
Test the Engine with Replaced Metering Valve

Perform the following steps to determine if the replaced metering valve has resolved lack of power condition: ‪

  1. Start and run the engine.
  2. Run the engine at idle with a no-load condition for approximately five minutes, allowing the engine coolant to reach normal operating range.
  3. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check for high fuel temperature return; refer to section .

Troubleshooting Procedure for High Fuel Temperature Return

To determine if high fuel temperature return is causing lack of power, perform the following steps: ‪

  1. Test for high fuel temperature return.
  2. Analyze the high fuel temperature test results.
    1. If the return fuel temperature is less than or equal to 60C (140F), check for air cleaner restriction; refer to section .
    2. If the return fuel temperature is greater than 60C (140F), resolve the high fuel temperature return condition; refer to section .

High Fuel Temperature Resolution

Perform the following steps to resolve high fuel temperature return: ‪

  1. Remove and replace fuel filter(s); refer to section .
  2. Verify high fuel temperature repair; refer to section .
Test the Engine with Resolved High Fuel Temperature

Perform the following steps to determine if high fuel temperature repairs have resolved lack of power condition: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If lack of power did not occur during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of occurred during the test drive, shut down the engine. Check for a restricted air cleaner element; refer to section .

Troubleshooting Procedure for Restricted Air Cleaner Element

To determine if a restricted air cleaner element is causing lack of power, perform the following steps: ‪

  1. Remove the air filter element from the air cleaner container; refer to OEMguidelines.
  2. Visually inspect the air cleaner element for damage or clogging.
    1. If no damage or clogging is found, check the charge air cooler; refer to section .
    2. If damage or clogging is found, refer to section .

Air Filter Element Replacement

Perform the following steps to replace the air filter element: ‪

  1. Remove and replace the damaged or clogged air filter element; refer to OEMguidelines.
  2. Verify air filter element replacement; refer to section .
Test the Engine with Replaced Air Filter Element

Perform the following steps to determine if the new air filter element has resolved lack of power: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If lack of power did not occur during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check the charge air cooler; refer to section .

Troubleshooting Procedure for Restricted or Cracked Charge Air Cooler or Leaking Intake Manifold

To determine if a restricted or cracked charge air cooler or leaking manifold is causing lack of power, perform the following steps: ‪

NOTICE:

To avoid engine damage, follow the installation instructions provided with the air-to-air charge air cooler test kit. ‪

  1. Attach a WK93 air-to-air charge air cooler test kit; refer to OEMguidelines.
  2. Disconnect the air inlet hose from the outlet side of the turbocharger compressor housing; refer to section .
  3. Attach the air-to-air cooler test kit adaptor plug to fit into the hose at the compressor connector; refer to OEMguidelines.
  4. Attach an air pressure hose to the air chuck at the regulator and gradually pressurize the air inlet system to a pressure of 177 kPa (26 psi).
  5. Apply a water and soap solution to each hose connection, across the face of the charge air cooler.
  6. Apply a water and soap solution to the air intake manifold and cylinder head mating surface area.
  7. Visually inspect all joints for air leaks and all charge air cooler welded surfaces for stress leaks.
    1. If air leaks are present around the joints, replace the charge air cooler; refer to section .
    2. If any leaks are present around the air intake manifold, replace gaskets and/or repair the air intake manifold accordingly; refer to section .
    3. If neither charge air cooler nor intake manifold leaked, check the exhaust system; refer to section .

Charge Air Cooler Replacement

Perform the following steps to replace the charge air cooler: ‪

  1. Remove and replace the charge air cooler; refer to OEMguidelines.
  2. If the intake manifold doesn't leak, verify replacement of the charge air cooler; refer to section .
  3. If the intake manifold leaks, repair intake manifold; refer to section .

Air Intake Manifold Repair

Perform the following steps to repair the air intake manifold: ‪

  1. Remove the air intake manifold:refer to section .
  2. Inspect the air intake manifold and gaskets.
  3. Install the air intake manifold with new gaskets; refer to section .
  4. Verify repair of the intake manifold; refer to section .
Test the Engine with Replaced Charge Air Cooler and Air Intake Manifold

To determine if the repairs resolved the lack of power condition, perform the following steps: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check the exhaust system; refer to section .

Troubleshooting Procedure for a Faulty Exhaust System

To determine if a faulty exhaust system is causing lack of power, perform the following steps: ‪

  1. Drill an 11/32 in. hole in the exhaust pipe, 125 - 305 mm (5 - 12 in.) from the turbocharger exhaust outlet.

    Note: The tapped hole must be in a comparatively straight area of the turbocharger exhaust outlet.

  2. Tap the hole to accommodate a 1/8 in. pipe plug.
  3. Connect a manometer to the tapped hole.
  4. Start and run the engine.
  5. Run the engine at idle with a no-load condition for approximately five minutes, allowing the engine coolant to reach normal operating range, approximately 88-96C (190-205F).
  6. Run the engine speed to full load.
    1. If the exhaust back pressure at full load is less than 12 kPa (3.5 in. Hg), check for high inlet air temperature; refer to section .
    2. If the exhaust back pressure at full load is 12 kPa (3.5 in. Hg) or greater, refer to section .

Engine Exhaust System Resolution

Perform the following steps to resolve the engine exhaust system concern: ‪

  1. Visually inspect the engine exhaust system; refer to OEMguidelines.
  2. Repair or replace defective exhaust system components; refer to OEMguidelines.
  3. Verify exhaust system resolution; refer to section .
Test the Engine with Replaced Exhaust System

Perform the following steps to determine if replaced engine exhaust system components have resolved the lack of power condition: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check for high inlet air temperature; refer to section .

Troubleshooting Procedure for High Inlet Air Temperature

To determine if high inlet air temperature is causing lack of power, perform the following steps: ‪

  1. Test/check the radiator fan, fan drive, or fan shroud for proper operation or configuration; refer to OEM guidelines.
    1. If the radiator fan, fan drive, or fan shroud pass the OEMtest, check camshaft timing; refer to section .
    2. If the radiator fan, drive or shroud did not operate correctly, refer to section .

Radiator Fan, Drive and Shroud Replacement

Perform the following steps to replace the radiator fan, drive, and or shroud: ‪

  1. Remove and replace the radiator fan, drive, and/or shroud; refer to OEMguidelines.
  2. Verify replacement; refer to section .
Test the Engine with Radiator Fan, Fan Drive, or Fan Shroud Replacement

Perform the following steps to determine if replaced radiator fan, fan drive, or fan shroud resolved lack of power condition: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Check camshaft timing; refer to section .

Troubleshooting Procedure for Incorrect Camshaft Timing

To determine if incorrect camshaft timing is causing lack of power, perform the following steps: ‪

  1. Check the camshaft timing; refer to section .
    1. If the dial indicator reading on the unit pump lobe is 13.8 mm (0.54 in.) or above, no further troubleshooting in required.
    2. If the dial indicator reading is not above 13.8 mm (0.54 in.), check engine timing; refer to section .

Engine Timing Resolution

Perform the following steps to resolve incorrect engine timing: ‪

  1. Perform an engine gear train timing check.
  2. Verify engine timing resolution; refer to section .
Test Engine with Correct Timing

Perform the following steps to determine if corrected engine timing has resolved lack of power condition: ‪

  1. Start and run the engine.
  2. Test drive the vehicle to ensure lack of power has been resolved.
    1. If no lack of power occurred during the test drive, no further troubleshooting is required. Shut down the engine.
    2. If lack of power occurred during the test drive, shut down the engine. Call Detroit Diesel Technical Service Group.