GM Metro/Sprint 1985-1993 Repair Guide

Diagnosis and Testing

Imprimir

IGNITION COIL TESTING



See Figures 1 and 2



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Fig. Fig. 1: Measuring ignition coil voltage



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Fig. Fig. 2: Measuring ignition coil resistance

  1. Check for spark at each spark plug with a spark plug tester. If no spark is detected, proceed to Step 2. If spark is only detected on some spark plugs, check for a faulty distributor cap or rotor. Also check the spark plugs and wires. Replace as needed.
  2.  
  3. Check for voltage at the ignition coil positive terminal with a voltmeter. If battery voltage is detected, proceed to Step 3. If battery voltage is not detected, repair the open in the wiring between the battery and the ignition coil.
  4.  
  5. Disconnect the connector on the negative coil wire. Check ignition coil resistance. If resistance is within specification, proceed to Step 4. If resistance is not within specification, replace the coil.
    1. Measure the resistance between the positive and negative terminals. Resistance should be 1.08-1.32 ohms electronic ignition with knock control and 1.33-1.55 ohms for all others.
    2.  
    3. Measure the resistance between the positive/negative terminals and the coil high tension wire terminal. Resistance should be 11.6-15.8 kilo-ohms for electronic ignition with knock control and 10.7-14.5 kilo-ohms for all others.
    4.  

  6.  
  7. On Conventional and ESC ignitions, check the resistance of the noise filter and condenser with an ohmmeter. If the resistance is 2.0-2.5 ohms for both units, proceed to Step 5. If the resistance is not within specification, replace both units as a set.
  8.  
  9. On Conventional ignitions, check the continuity of the brown/white wire between the ignition coil negative terminal and the distributor. If continuity exists, replace the pick-up coil and igniter. If continuity does not exist, repair the open in the wire.
  10.  

KNOCK CONTROL SYSTEM TESTING



See Figure 3



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