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Basic Testing Procedure

  1. An electronic fuel feedback tester (ET 501) is available to aid in system diagnosis. If tester is not available, test No. 1 should be performed first, then tests No. 3, 4, 6, 8A, 8B and 9. These series of tests will provide a thorough system diagnosis.
  2. The steps listed in the charts will provide a systematic evaluation of each component that could cause a malfunction. After completing a repair, repeat the test to ensure that the malfunction has been corrected.
  3. Before performing any of the tests, make sure that the following related systems are operating properly:
    • Basic carburetor adjustments.
    • Mechanical engine operation (plugs, valves, rings).
    • Ignition system.
    • Intake manifold, carburetor or base plate gaskets.
    • Loose vacuum hoses or fittings.
Fig 1: Diagnostic Connector Pin Locations These diagnostic connectors are used on 4-cylinder engines.
G9497