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Engine Controls - Tests W/o Codes - 7.3L Diesel: Diagnosis Ford Econoline E350

Testing & Diagnostics ~1676 words

SYMPTOM DIAGNOSIS

Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in TESTS W/CODES - 7.3L DIESEL article were performed before diagnosing a symptom. Symptoms available for diagnosis are as follows

  1. No Crank/Slow Crank
  2. Stalls After Start
  3. No Start/Normal Crank Or Hard Start/Long Crank
  4. Engine Will Only Idle
  5. Slow Return To Idle
  6. Rough Idle/Stalls When Engaging Clutch
  7. Fast Idle
  8. Runs Rough, Misses, Buck/Jerk, Hesitation Or Stumbles
  9. Surge (On Acceleration Or Cruise)
  10. Loss Of Power/Poor Fuel Economy
  11. Malfunction Indicator Light (MIL)
  12. Exhaust Smoke
  13. Cruise (Speed) Control Inoperative
  14. Transmission Control Indicator Light (TCIL)
  15. Improper Transmission Shift
  16. High Oil Consumption/Leaks
  17. Hard Start/No Start - Dry Reservoir

Symptom Checks

Perform the following

  1. Check starter relay.
  2. Check starting system (starter, starter ground and battery cables).
  3. Check charging system.
  4. Check for seized/hydrostatic locked engine (leaking injectors).
  5. Check for defective flywheel/flexplate or seized engine components.
  6. Check ignition circuit. In particular, check for ignition starter wire shorting to ground.
  7. Check transmission linkage adjustment or Transmission Range (TR) sensor adjustment. See ADJUSTMENTS in AUTOMATIC TRANSMISSION article in the TRANSMISSION SERVICING section.

Perform the following

  1. If engine stalls with engine oil temperature at less than 32°F (0°C), oil return to oil pan may be too slow. Ensure proper oil viscosity is being used for frigid conditions.
  2. Perform ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  3. On A/T models, if no faults are found after performing ENGINE PERFORMANCE DIAGNOSIS, check transmission operation.

Perform the following

  1. Check engine oil level in high pressure oil pump reservoir. Oil level should be within 1" (25.4 mm) of top of reservoir.
  2. If oil level is low, refill and attempt to start engine. If engine starts after about 15 seconds, high pressure oil pump is not supplying enough oil pressure. Perform «HARD START/NO START - DRY RESERVOIR»(ref-24262-S36384752932001010400000) symptom check.
  3. Perform KOEO ON-DEMAND SELF-TEST. See QUICK TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If any diagnostic trouble codes are present, perform appropriate circuit test.
  4. Perform KOEO INJECTOR ELECTRICAL SELF-TEST. See QUICK TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If any diagnostic trouble codes are present, perform appropriate circuit test. If test does not run, repeat KOEO INJECTOR ELECTRICAL SELF-TEST for each injector with one injector connector disconnected at a time. If KOEO INJECTOR ELECTRICAL SELF-TEST now runs, remove valve cover and inspect disconnected valve cover wiring harness for a pinched or grounded injector wire. If KOEO INJECTOR ELECTRICAL SELF-TEST still does not run, check Injector Driver Module (IDM) power and ground circuits. See CIRCUIT TEST NC in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. Check for short to ground in IDM or injector circuits. See CIRCUIT TEST NA, step 29).
  5. Check Parameter Identifications (PIDs) during cranking. See CHECK PARAMETER IDENTIFICATION (PID) DURING CRANKING under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  6. Perform GLOW PLUG SYSTEM OPERATION TEST under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  7. Perform appropriate fuel pump pressure test. See FUEL PUMP PRESSURE TEST under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.

Perform the following

  1. Check if Accelerator Pedal (AP) sensor is mounted correctly. AP sensor is located above accelerator pedal.
  2. Check Idle Validation Switch (IVS). See CIRCUIT TEST FE in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  3. Ensure floor mats do not interfere with accelerator pedal.
  4. Ensure accelerator pedal is not damaged.

Perform the following

  1. Check for floor mat interference.
  2. Check for defective accelerator pedal bushing.
  3. Check for overfilled crankcase.
  4. Check for coolant in oil.
  5. Check crankcase for fuel contamination.
  6. Check Engine Oil Temperature (EOT) sensor. See CIRCUIT TEST DB in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If EOT sensor is okay, perform «LOSS OF POWER/POOR FUEL ECONOMY»(ref-24262-S11498194832001010400000) symptom check.

Perform the following

  1. Perform KOEO ON-DEMAND SELF-TEST. See QUICK TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  2. Perform KOEO INJECTOR ELECTRICAL SELF-TEST. See QUICK TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  3. Check for aerated oil. See INJECTION CONTROL PRESSURE TESTS under ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  4. Perform CIRCUIT TEST DD in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  5. Check fuel pump pressure.
  6. Check for restricted fuel line.
  7. Check fuel regulator for blockage.
  8. Check engine oil level in high pressure oil pump reservoir. Oil level should be within 1" (25.4 mm) of top of reservoir.
  9. Check engine oil pressure. Should be a minimum of 10 psi at idle. If oil pressure is low, check engine mechanical condition for cause of low oil pressure.
  10. Perform INJECTION CONTROL PRESSURE LEAK TEST under HARD START/NO-START DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  11. Perform KOER CYLINDER CONTRIBUTION TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  12. On M/T models, check for defective dual mass flywheel. See appropriate article in the CLUTCHES section.
  13. Check for incorrect injector application. Injector part numbers are stamped on top of injector.

Perform the following

  1. With engine at normal operating temperature, check EOT PID reading. See ADDITIONAL SYSTEM FUNCTIONS in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If EOT PID reading is less than 100°F (38°C), replace EOT sensor.
  2. Check for floor mat interference.
  3. Check for defective accelerator pedal bushing.
  4. Check for overfilled crankcase.
  5. Check for coolant in oil.
  6. Check crankcase for fuel contamination.

Perform the following

  1. Perform LOSS OF POWER/POOR FUEL ECONOMY symptom check.
  2. On A/T models, if no faults are found after performing LOSS OF POWER/POOR FUEL ECONOMY, check transmission operation.

Perform the following

  1. Perform LOSS OF POWER/POOR FUEL ECONOMY symptom check.
  2. On A/T models, if no faults are found after performing LOSS OF POWER/POOR FUEL ECONOMY, check transmission operation.

Perform the following

  1. Check if engine oil has been changed within 5000 miles.
  2. Check air restriction gauge, located on air filter housing, to determine if air cleaner needs replacement.
  3. Check for correct Manifold Absolute Pressure (MAP) sensor.
  4. Check for intake manifold leaks.
  5. Perform KOEO ON-DEMAND SELF-TEST and KOEO INJECTOR ELECTRICAL SELF-TEST. See QUICK TEST in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  6. Check camshaft timing.
  7. Check for biased Injection Control Pressure (ICP) sensor. See CIRCUIT TEST DD in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  8. Check fuel pressure.
  9. Check for restricted exhaust system. See CHECK FOR EXHAUST RESTRICTION under ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  10. Check for aerated engine oil. See INJECTION CONTROL PRESSURE TESTS under ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  11. Check for biased Exhaust Backpressure (EBP) sensor. See CIRCUIT TEST DF in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  12. Perform CIRCUIT TEST B in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  13. Perform KOER CYLINDER CONTRIBUTION TEST. See «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  14. Check engine mechanical condition.
  15. Check turbo boost. See BOOST PRESSURE TEST under ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  16. Check MAP sensor. See CIRCUIT TEST DC (models with mechanical fuel pump) or CIRCUIT TEST DJ (models with electric fuel pump) in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  17. Perform CIRCUIT TEST D in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  18. Check for biased Engine Oil Temperature (EOT) sensor. See CIRCUIT TEST DB in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.

Perform the following

  1. If MIL is always on, check for Diagnostic Trouble Codes (DTCs). See «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If any DTCs are present, perform appropriate circuit test.
  2. Cycle ignition switch. If MIL light turns on then goes out (bulb check), no problem is indicated.
  3. If MIL is always off, perform CIRCUIT TEST NB in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.

Perform the following

  1. If ABS light is on, service ABS system as necessary.
  2. If BRAKE warning light is on, go to CIRCUIT TEST FF in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article.
  3. Check PBA, BPA, CPP, BOO, SCCS M and VSS Parameter Identification (PID). See ADDITIONAL SYSTEM FUNCTIONS in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If any PID value is incorrect, perform appropriate circuit test.
  4. Perform «LOSS OF POWER/POOR FUEL ECONOMY»(ref-24262-S11498194832001010400000) symptom check.

Perform the following

  1. If TCIL is flashing and Malfunction Indicator Light (MIL) is also on, perform «MALFUNCTION INDICATOR LIGHT (MIL)»(ref-24262-S03819727702001010400000) symptom check.
  2. Check TCIL circuit. See TRANSMISSION SERVICE & REPAIR article.

Perform the following

  1. Check TR, SCCS M, 4X4L and VSS Parameter Identification (PID). See ADDITIONAL SYSTEM FUNCTIONS in «TESTS W/CODES - 7.3L DIESEL»(ref-24260) article. If any PID value is incorrect, perform appropriate circuit test.
  2. Check for transmission codes. Service codes as necessary. See TRANSMISSION SERVICE & REPAIR article.

Perform the following

  1. Perform ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  2. Check engine mechanical condition. Check valves, valve guides, valve stem oil seals, intake manifold gaskets, cylinder head oil drain passages and piston rings.

Perform the following

  1. Perform INJECTION CONTROL PRESSURE TESTS under ENGINE PERFORMANCE DIAGNOSIS in «SYSTEM/COMPONENT TESTS - 7.3L DIESEL»(ref-24265) article.
  2. Check engine oil level in high pressure oil pump reservoir. Oil level should be within 1" (25.4 mm) of top of reservoir. Drive vehicle for 10 miles. Recheck high pressure oil pump reservoir. If oil level is low, check oil reservoir and engine front cover for oil leakage. Repair as necessary.
  3. Allow vehicle to sit overnight. Recheck engine oil level in high pressure oil pump reservoir. If oil level is low, remove high pressure oil pump. Check for high pressure oil pump gasket for signs of internal oil leak. Check high pressure oil pump reservoir for casting porosity. Repair as necessary.

INTERMITTENT PROBLEM DIAGNOSIS

Intermittent fault testing requires duplicating circuit or component failure to identify problem. These procedures may lead to the computer setting a fault code (on some systems), which may help in diagnosis.

If problem vehicle does not produce fault codes, monitor voltage or resistance using a DVOM while attempting to reproduce conditions causing intermittent fault. A status change on DVOM indicates a fault has been located.

Use a DVOM to pinpoint faults. When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance. Status changes on DVOM during test procedures indicate area of fault.

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