GM Prizm/Nova 1985-1993 Repair Guide

Diagnosis and Testing - Prizm

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ENGINE CRANKS BUT DOES NOT START



1989-92

See Figures 1 through 5

  1. Check for spark at each spark plug with a spark tester. Check at least 2 plug wires.
  2.  
  3. If spark is only detected at some plugs, check for a faulty distributor cap or rotor. Also check the spark plugs and plug wires. Replace, if necessary.
  4.  
  5. If no spark is detected, with the ignition switch at the ON position, check for voltage at the ignition coil positive (+) terminal, using a digital voltmeter.
  6.  
  7. If battery voltage is not indicated, repair the open circuit between the battery and the ignition coil.
  8.  
  9. If battery voltage is detected, check the ignition coil resistance.
    1. Turn the ignition switch to the OFF position.
    2.  
    3. Check that the primary coil resistance is between 1.28-1.56 ohms.
    4.  
    5. Check that the secondary coil resistance is between 10,400-14,000 ohms.
    6.  

  10.  
  11. If the coil resistance is not within specification, replace the ignition coil.
  12.  
  13. If the coil resistance is within specification, disconnect the pickup coil connector. Measure the resistance between terminals 2 and 3 (1989-90 vehicles) or terminals 5 and 6 (1990-92 VIN Code 6 engines) or either terminal (1990-92 VIN Code 5 engines). If the resistance is not 140-180 ohms, replace the distributor.
  14.  
  15. If the resistance is within 140-180 ohms, measure the resistance between the pickup coil connector terminals 1 and 3 (1989-90 vehicles), terminals 2 and 5 (1991-92 VIN Code 6 engines) or either terminal (1990-92 VIN Code 5 engines). If the resistance is not 140-180 ohms, replace the distributor.
  16.  
  17. If the resistance is within 140-180 ohms, reconnect the pickup coil connector and check the signal rotor air gap. If the signal rotor air gap is not 0.008-0.016 inch (0.2-0.4 mm), replace the distributor.
  18.  
  19. If the signal rotor air gap is within 0.008-0.016 inch (0.2-0.4 mm), substitute a known good igniter.
  20.  
  21. If the vehicle starts, install an igniter.
  22.  
  23. If the vehicle still does not start, reinstall the original igniter. The problem is in the wiring between the ignition system and the ECM or with the ECM itself.
  24.  



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Fig. Fig. 1: Measuring the pickup coil resistance - 1989-90 VIN Code 6 engine



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Fig. Fig. 2: Measuring the pickup coil resistance - 1991-92 VIN Code 6 engines



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Fig. Fig. 3: Checking the air gap on the 1989-92 VIN Code 6 engines



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Fig. Fig. 4: Measuring the air gap - 1990-92 VIN Code 5 engines



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Fig. Fig. 5: Pickup coil connectors - 1990-92 VIN Code 5 engines

1993

See Figures 6 and 7

  1. Check for spark at each spark plug with a spark tester. Check at least 2 plug wires.
  2.  
  3. If spark is only detected at some plugs, check for a faulty distributor cap or rotor. Also check the spark plugs and plug wires. Replace, if necessary.
  4.  
  5. Measure the resistance of the distributor connector C1 when cold, between terminals 3 and 6, using a digital voltmeter. If the camshaft position (CMP) sensor resistance is not between 185-275 ohms, replace the distributor housing.
  6.  
  7. Measure the resistance of the distributor connector C1 when cold, between terminals 2 and 5, using a digital voltmeter. If the camshaft position (CMP) sensor resistance is not between 370-550 ohms, replace the distributor housing.
  8.  
  9. Measure the resistance of the distributor connector C1 when hot, between terminals 3 and 6, using a digital voltmeter. If the camshaft position (CMP) sensor resistance is not between 240-325 ohms, replace the distributor housing.
  10.  
  11. Measure the resistance of the distributor connector C1 when hot, between terminals 2 and 5, using a digital voltmeter. If the camshaft position (CMP) sensor resistance is not between 475-650 ohms, replace the distributor housing.
  12.  
  13. Measure the air gap between the signal rotor and the camshaft position (CMP) sensor. If the air gap is not 0.008-0.016 inch (0.2-0.4 mm), replace the distributor housing.
  14.  



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Fig. Fig. 6: Measuring the Camshaft Position (CMP) sensor resistance - 1993 engines



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Fig. Fig. 7: Measuring the air gap - 1993 engines

 
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