LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2004 >> Taurus LX, 3.0 2 >> Repair and Diagnosis >> External Pages >> Different car >> Section 168 (Engine Controls - Trouble Shooting - No Codes - 6.0L (99P F450/550) Diesel) >> Symptoms >> Runs Rough, Misses, Bucks Or Jerks, Hesitation, Stumbles, Surges (On Acceleration Or Cruise), Lack Or Loss Of Power, Or Poor Fuel Economy

Runs Rough, Misses, Bucks Or Jerks, Hesitation, Stumbles, Surges (On Acceleration Or Cruise), Lack Or Loss Of Power, Or Poor Fuel Economy

WARNING: This page is about a different car, the 2003 Ford Pickup, 2003 Ford F550 Super Duty, 2003 Ford F450 Super Duty, 2003 Ford Excursion, and 2003 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: The Powertrain Control Module (PCM) is equipped with an over RPM/speed limiting function that will shut off fuel delivery when predetermined engine speed is exceeded.

  1. Preliminary Checks

    Check brakes for dragging. Check transmission and axle fluid levels. Ensure transmission and axle bearings have not been overheated. Check for oil in coolant. Ensure engine oil level, viscosity and API rating meets specification. Ensure engine oil has been changed within last 5000 miles. Check air filter minder to see if filter needs to be replaced. Check Manifold Absolute Pressure (MAP) sensor hose for cracks, blockages or disconnection. Check intake manifold for leaks or restrictions. Check fuel quality. See TEST 2: SUFFICIENT CLEAN FUEL under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Check vehicles laden weight with operator's expectations of vehicle performance. Check for engine overheating. Check wiring harness connectors for corroded, loose or damaged terminals. Repair any problems as necessary. If no problems are indicated, go to next step.

  2. Perform KOEO On-Demand Self-Test

    Perform KOEO ON-DEMAND SELF-TEST under QUICK TEST in SELF-DIAGNOSTICS - 6.0L DIESEL article. If no DTCs are present, go to next step. If any DTCs are present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.0L DIESEL article and perform appropriate SYSTEM TESTS.

  3. Perform KOEO Injector Electrical Self-Test

    Perform KOEO INJECTOR ELECTRICAL SELF-TEST under QUICK TEST in SELF-DIAGNOSTICS - 6.0L DIESEL article. If no DTCs are present, go to next step. If any DTCs are present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.0L DIESEL article and perform appropriate SYSTEM TESTS.

  4. Check Continuous Memory DTCs

    If any other Continuous Memory DTCs are present, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 6.0L DIESEL article. If no other Continuous Memory DTCs are present, go to next step.

  5. Check For Biased ICP Sensor

    Perform TEST Q: INJECTION CONTROL PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair any problems as necessary. If no problems are indicated, go to next step.

  6. Check Fuel Pump Pressure

    Perform TEST 10: ELECTRIC FUEL PUMP PRESSURE under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Repair any problems as necessary. If fuel pump pressure is okay, go to next step.

  7. Check Fuel Regulator

    Check fuel regulator valve for sticking or contamination. Check fuel regulator "O" rings for damage. If fuel regulator valve or fuel regulator valve "O" rings require service, replace fuel regulator valve as a unit. If both fuel regulator valve and "O" rings are okay, go to next step.
    8. NOTE: Air may be present due to a recent repair on injection control pressure system. It may be necessary to drive vehicle aggressively for 15-20 miles to remove air from system. Engine must be at operating temperature prior to running aeration tests.

  8. Check For Aerated Engine Oil
    Perform TEST 18: OIL AERATION TEST under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Repair any problems as necessary. If no problems are indicated, go to next step.

  9. Injection Control Pressure Test

    Perform TEST 14: LOW IDLE STABILITY (ICP PRESSURE) under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Repair any problems as necessary. If no problems are indicated, go to next step.

  10. Check For Low FICM Power

    Perform TEST S: FICM CIRCUIT LOW VOLTAGE under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair any problems as necessary. If no problems are indicated, go to next step.

  11. Check Lubrication Pressure

    Remove oil pressure sender. Oil pressure sender is located on top of engine behind oil filter. Connect an oil pressure gauge to oil pressure sender galley port. Run engine until operating temperature is reached. With engine idling, engine oil pressure should be 10 psi (69 kPa) or more. If engine oil pressure is as specified, go to next step. If engine oil pressure is not as specified, check for cause of low oil pressure and repair as necessary.

  12. KOER On-Demand Self-Test

    Ensure engine is at normal operating temperature. Clear DTCs. Perform KOER ON-DEMAND SELF-TEST under QUICK TEST in SELF-DIAGNOSTICS - 6.0L DIESEL article. If DTC P2291 is present, perform TEST 10C: MONITOR ICP PID WHILE CRANKING under HARD START/NO-START DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. If DTC P0471 is present, perform TEST X: EXHAUST PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. If no DTCs are present, perform TEST 17: CRANKCASE PRESSURE TEST under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. Repair any problems as necessary. If symptom persists, go to next step.

  13. Check Pressure Balance

    Remove valve covers. Remove high pressure hose from right cylinder head. Plug high-pressure hose for right cylinder head using plug from Oil High Pressure Leakage Test Adapter Set (303-756). See Figure. Record IPR at 3,000 RPM. Plug high-pressure hose for left cylinder head and reattach high-pressure hose on right cylinder head. Record IPR at specified RPM. If IPR duty cycle difference is greater than 2 percent, go to next step. If it is not, install a new IPR.

  14. Check For Leak Source

    On the cylinder bank with higher IPR duty cycle, with engine idling, check for bubbling around injector bores or oil gallery drain plugs. If bubbles are noticeable or leaks are heard, replace "O" rings on injectors or reseal oil galleries as necessary. If no leaks are detected, go to ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article.

  15. Check For Biased EBP Sensor

    Perform TEST X: EXHAUST PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair circuits or replace EBP sensor as necessary. If EBP sensor is okay, go to next step.

  16. Check For Engine Wear

    Perform TEST 17: CRANKCASE PRESSURE TEST under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL article. If crankcase pressure reading is more than 3 in. H2O, go to next step to check engine mechanical condition. If crankcase pressure reading is 3 in. H2O or less, go to next step.

  17. Check For Piston Or Valve Leaks

    Check engine compression. If compression reading is less than 350 psi (2413 kPa) and different from adjacent cylinders by 50 psi (345 kPa) or more, repair engine mechanical condition as necessary. See appropriate article in ENGINES. If compression reading is 350 psi (2413 kPa) or more and different from adjacent cylinders by less than 50 psi (345 kPa), go to next step.

  18. Check For Exhaust Restriction

    Measure Exhaust Pressure (EP). If EP is greater than 34 psi (234 kPa), locate and repair restriction in exhaust system. Verify repair. If EP is okay, go to next step.

  19. Atmospheric Pressure Rationality Check

    Turn ignition on. Using scan tool, monitor EP, MAP and BARO PIDs. PID values should not deviate from atmospheric pressure by more than 1.5 psi (10 kPa). If all PID values are within specification, go to next step. If any PID value is not within specification, perform appropriate system test for the sensor with the largest difference. If EP PID value is not within specification, see TEST X: EXHAUST PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. If MAP PID value is not within specification, see TEST E: MANIFOLD ABSOLUTE PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. If BARO PID value is not within specification, see TEST H: BAROMETRIC PRESSURE SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article.

  20. Check For Biased EOT Sensor

    Perform TEST L: ENGINE OIL TEMPERATURE SENSOR , step 17  under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair as necessary. If EOT sensor is okay, go to next step.

  21. Check EOT Sensor Rationality

    Perform TEST L: ENGINE OIL TEMPERATURE SENSOR , step 18  under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair as necessary. If EOT sensor is okay, go to next step.

  22. Transmission Concerns

    See appropriate DIAGNOSIS article in AUTOMATIC TRANSMISSIONS. Repair as necessary. If transmission is okay, go to next step.

  23. Check EGR Operation

    Perform TEST 8: EGR POSITION under ENGINE PERFORMANCE DIAGNOSTIC PROCEDURES in SYSTEM & COMPONENT TESTING - 6.0L DIESEL. Repair as necessary. If EGR is okay, go to next step.

  24. Check Mass Air Flow Performance

    Perform TEST J: MASS AIR FLOW SENSOR under SYSTEM TESTS in SELF-DIAGNOSTICS - 6.0L DIESEL article. Repair as necessary.
scientia non olet · About LEMON Manuals