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Preparation For Checks

  1. Frequency valve is operated by pulsating voltage from ECU. By measuring this signal, mixture function of system can be tested and changed. Voltmeter is used to check and adjust frequency valve control and duty cycle. High-quality dwell meter may be used on all other models.
  2. Connect tachometer and oil temperature gauge. Ensure A/C is off and transmission lever is in Park. If available, insert voltmeter test plug into diagnostic plug and connect voltmeter negative (Black) lead to test plug. If test plug is not available, connect negative lead to No. 3 pin of diagnostic socket. Positive (Red) lead of voltmeter should be connected to battery voltage source.
  3. Throttle valve lever must be against idle stop. Accelerator Bowden cable must be tension free at throttle lever. Adjust if necessary. Engine oil must be at operating temperature of 176°F (80° C). Run engine at idle and turn off all electrical consumers. Check and adjust idle speed if necessary.
  4. Connect dwell meter to 2-wire testing connector.
  5. The color-coded wire should be connected to positive (+) lead of dwell meter. Other wire in connector is ground and should be connected to negative (-) lead of dwell meter. Set dwell meter on 4-cylinder scale. Start engine and run until warm.
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