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Diagnosis & Repair

WARNING: This page is about a different car, the 2000 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check vacuum hoses for leaks, blockage and proper routing. See VACUUM DIAGRAMS article. Also, check wiring and connectors for damage or poor connections. If problem exists, repair as necessary and perform TEST DRIVE CONFIRMATION . If problem does not exist, go to next step.
  2. Check spark and ignition system. See IGNITION SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If problem exists, repair as necessary. If problem does not exist, go to next step.
  3. Access ECM behind passenger's side kick panel. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between ground and fuel injector terminals at specified ECM harness connector. See IDENTIFYING FUEL INJECTOR TERMINALS  table. See Figure. If voltage is 9-14 volts at each terminal, go to step  6. If voltage is not 9-14 volts at each terminal, go to next step.
    IDENTIFYING FUEL INJECTOR TERMINALS

    Fuel Injector No. ECM Terminal No. Wire Color
    1 (1) 5 Blue
    2 (1) 6 Red
    3 (2) 1 Yellow
    4 (2) 2 White
    5 (2) 3 Green
    6 (2) 4 Green
    (1) Terminal are located in ECM harness connector E5. See Figure.
    (2) Terminals are located in ECM harness connector E4. See Figure.
  4. Disconnect fuel injector harness connector at misfiring cylinder. Measure resistance between fuel injector terminals (component side). Resistance should be 13.4-14.2 ohms at 68°F (20°C). If resistance is as specified, go to next step. If resistance is not as specified, replace fuel injector.
  5. Check for open or short in wiring between ECM and fuel injector. See WIRING DIAGRAMS article. If problem exists, repair as necessary. If problem does not exist, repair open or short in fuel injector power source circuit. See WIRING DIAGRAMS article.
  6. Check fuel pressure. See FUEL SYSTEMS in BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If fuel pressure is not within specification, repair as necessary. If fuel pressure is within specification, go to next step.
  7. Check fuel injectors. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING - V6 & V8 article. If problem exists, repair as necessary. If problem does not exist, go to next step.
  8. Check Mass Airflow (MAF) meter and Engine Coolant Temperature (ECT) sensor. See ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - V6 & V8 article. If problem exists, replace appropriate component. If problem does not exist, go to next step.
  9. Check engine compression. See BASIC DIAGNOSTIC PROCEDURES - V6 & V8 article. If engine compression is okay, check valve clearance. See ON-VEHICLE ADJUSTMENTS - V6 & V8 article. If valve clearance is okay, it may be necessary to check valve timing. See appropriate article in ENGINES.
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