1990 Toyota Corolla Base, AutomaticFACTORY OEM SERVICE PROCEDURE

Fuel Injector Check

  1. Turn ignition off. Unplug each injector connector. Measure resistance across both terminals. Resistance should be 13.8 ohms at 68°F (20°C).
  2. To check injector spray pattern and volume, relieve fuel system pressure and remove injectors from engine. Disconnect fuel hose from fuel filter outlet. Use Fuel Injection Kit (09268-41080) to tee fuel injector between fuel filter and fuel pressure regulator.
  3. Place injector into a graduated container. Place vinyl tube on end of injector to prevent fuel from splashing out.
  4. Hook up Fuel Injector Tester (09842-30070) or trigger box with appropriate resistor to fuel injector. Turn ignition on, with engine off.
  5. Connect jumper wire to engine check connector terminals "FP" and "+B" to pressurize fuel system. For engine check connector locations, see Fig 1. Connector terminals are marked on inside of check connector cover. Fuel pump check connector is 2-wire connector near airflow meter in left rear corner of engine compartment (White/Black and Green wires).
    Fig 1: Location of Check Connector
    G95404Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. Trigger injector for 15 seconds. Measure volume and check spray pattern. Test each injector 2-3 times. Replace injector if volume is not as specified. See FUEL INJECTOR VOLUME SPECIFICATIONS  table.
    FUEL INJECTOR VOLUME SPECIFICATIONS

    Model Cu. In. (cc)
    4WD 4A-FE 2.4-3.1 (40-50)
    2WD 4A-GE 2.7-3.4 (45-55)
    Difference Between Each Injector .3 (5)
  7. Disconnect injector trigger. Fuel leakage from end of injector should be one drop or less in one minute. See Fig 3. Replace injector if leakage is more than specified.
Fig 2: Connecting Battery to Test Fuel Injector Spray Pattern
G118929Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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