Suzuki Samurai/Sidekick/Tracker 1986-1998 Repair Guide

Ignition Timing

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GENERAL INFORMATION



Ignition timing is the measurement, in degrees of crankshaft rotation, of the point at which the spark plugs fire in each of the cylinders. It is measured in degrees before or after Top Dead Center (TDC) of the compression stroke.

Because it takes a fraction of a second for the spark plug to ignite the mixture in the cylinder, the spark plug must fire a little before the piston reaches TDC. Otherwise, the mixture will not be completely ignited as the piston passes TDC and the full power of the explosion will not be used by the engine.

The timing measurement is given in degrees of crankshaft rotation before the piston reaches TDC (BTDC). If the setting for the ignition timing is 5° BTDC, the spark plug must fire 5° before each piston reaches TDC. This only holds true, however, when the engine is at idle speed.

As the engine speed increases, the pistons go faster. The spark plugs have to ignite the fuel even sooner if it is to be completely ignited when the piston reaches TDC.

If the ignition is set too far advanced (BTDC), the ignition and expansion of the fuel in the cylinder will occur too soon and tend to force the piston down while it is still traveling up. This causes engine ping. If the ignition spark is set too far retarded, after TDC (ATDC), the piston will have already passed TDC and started on its way down when the fuel is ignited. This will cause the piston to be forced down for only a portion of its travel. This will result in poor engine performance and lack of power.

Timing marks consisting of O marks or scales can be found on the rim of the crankshaft pulley and the timing cover. The mark(s) on the pulley correspond(s) to the position of the piston in the number 1 cylinder. A stroboscopic (dynamic) timing light is used, which is hooked into the circuit of the No. 1 cylinder spark plug. Every time the spark plug fires, the timing light flashes. By aiming the timing light at the timing marks while the engine is running, the exact position of the piston within the cylinder can be easily read since the stroboscopic flash makes the pulley appear to be standing still. Proper timing is indicated when the mark and scale are in proper alignment.

Because these vehicles utilize high voltage, electronic ignition systems, only a timing light with an inductive pick-up should be used. This pick-up simply clamps onto the No. 1 spark plug wire, eliminating the adapter. It is not susceptible to cross-firing or false triggering, which may occur with a conventional light, due to the greater voltages produced by electronic ignition.



Click image to see an enlarged view

Fig. Fig. 1: The vehicle information label, located under the hood, provides important tune-up specifications

INSPECTION & ADJUSTMENT



Since manufacturing specifications often change during the model-year, refer to the Vehicle Emission Control Information (VECI) label, located in the engine compartment, for your engine's specific ignition timing specification, prior to adjusting the ignition timing. If the specification indicated on your vehicle's VECI label differs from that given in this procedure, use the VECI label specification.

1986-88 1.3L Engines

See Figures 2 and 3

  1. Remove the rubber plug from the ignition timing inspection hole in the transmission housing (located near the engine/transmission flange).
  2.  
  3. Start the engine and allow it to warm up to normal operating temperature.
  4.  
  5. Be sure that all of the electrical loads, except for the ignition switch, are OFF. If equipped, ensure that the air conditioning is OFF.
  6.  
  7. Apply the parking brake and place the gearshift in Neutral.
  8.  
  9. Check the idle speed to ensure that it is 750-850 rpm. If it is not, adjust the idle speed prior to adjusting ignition timing.
  10.  
  11. Turn the ignition switch OFF .
  12.  
  13. Install the inductive timing light according to the manufacturer's instructions. The timing light input lead should always be attached to the No. 1 cylinder spark plug wire.
  14.  
  15. Start the engine and allow it to idle.
  16.  


CAUTION
When using the timing light, be sure to keep yourself and all tools away from moving and hot engine components. Do not wear loose clothing when working around a running engine, otherwise personal injury or death may result.



Click image to see an enlarged view

Fig. Fig. 2: The ignition timing inspection hole is located on the transmission, near the engine flange-the ignition is correctly set when the 10 degree BTDC mark is aligned with the matchmark at 750-850 rpm

  1. Use the timing light to read the ignition timing by pointing the light at the ignition timing inspection hole and pulling the light's trigger. If the 10 degree BTDC mark is aligned with the timing match mark on the transmission housing, the ignition timing is correct. Otherwise, adjust the ignition timing as follows:
    1. Loosen the distributor flange bolt.
    2.  
    3. Rotate the distributor housing until the ignition timing is within specifications. Turn the distributor counterclockwise to advance, and clockwise to retard the ignition timing.
    4.  

  2.  



Click image to see an enlarged view

Fig. Fig. 3: To adjust the ignition timing, loosen the flange bolt(s) and rotate the distributor housing accordingly

  1. Tighten the distributor flange bolt securely.
  2.  
  3. After adjusting the ignition timing and tightening the distributor flange bolts, recheck the ignition timing to ensure that it did not change while tightening the distributor flange bolts.
  4.  
  5. Shut the engine OFF , then remove the inductive timing light from the vehicle. Install the ignition timing inspection hole plug.
  6.  

1989-95 1.3L Engines

See Figures 4 and 5

  1. Start the engine and allow it to warm up to normal operating temperature.
  2.  
  3. Turn off the engine, turn the ignition switch ON for 5 seconds, then start the engine again and run it at 2000 rpm for 5 minutes. This will ensure that the engine is properly warmed up.
  4.  
  5. Be sure that all of the electrical loads, except for the ignition switch, are OFF. If equipped, ensure that the air conditioning is OFF.
  6.  
  7. Apply the parking brake and place the gearshift in Neutral (manual transmissions) or Park (automatic transmissions).
  8.  
  9. Check the idle speed to ensure that it is 800 rpm. If it is not, adjust the idle speed prior to adjusting ignition timing.
  10.  
  11. Turn the ignition switch OFF .
  12.  
  13. Install the inductive timing light according to the manufacturer's instructions. The timing light input lead should always be attached to the No. 1 cylinder spark plug wire.
  14.  
  15. Remove the cover from the monitor connector, located beside the right-hand head light assembly, and, using a jumper wire, connect terminals C and D . Grounding terminal C to terminal D will fix the ignition timing (prevent the timing from moving).
  16.  



Click image to see an enlarged view

Fig. Fig. 4: To prevent the ignition timing from fluctuating while checking it, use a jumper wire to ground monitor connector terminal D to terminal C

  1. Start the engine and allow it to idle.
  2.  


CAUTION
When using the timing light, be sure to keep yourself and all tools away from moving and hot engine components. Do not wear loose clothing when working around a running engine, otherwise personal injury or death may result.

  1. Use the timing light to read the ignition timing by pointing the light at the timing marks (located on the crankshaft pulley and timing belt cover tab) and pulling the light's trigger.
  2.  

If the timing fluctuates or changes, terminal D is not properly grounded to terminal C .

  1. If the ignition timing, with terminal D properly grounded, is not 7-9 degrees BTDC at 800 rpm engine speed, adjust the timing.
  2.  



Click image to see an enlarged view

Fig. Fig. 5: The ignition timing marks are stamped in a tab protruding from the timing belt cover, above the crankshaft pulley

  1. To adjust the ignition timing, loosen the distributor flange bolts and rotate it until the proper ignition timing is within specifications. Turn the distributor counterclockwise to advance, and clockwise to retard the ignition timing. Tighten the distributor flange bolts securely.
  2.  
  3. After adjusting the ignition timing and tightening the distributor flange bolts, recheck the ignition timing to ensure that it did not change while tightening the distributor flange bolts.
  4.  
  5. Detach the jumper wire from the monitor connector.
  6.  

With this jumper wire removed, the ignition timing may fluctuate, which is normal.

  1. Observe the ignition timing marks with the timing light while increasing engine speed. The ignition timing should advance as the engine speed increases. If the engine speed does not advance, inspect the TP sensor, the test switch terminal circuit, the engine start signal circuit and PCM.
  2.  


WARNING
Driving the vehicle with the monitor connector terminals grounded will result in catalytic converter damage; be sure to remove the jumper wire prior to driving the vehicle.

  1. Shut the engine OFF , then remove the inductive timing light from the vehicle. Install the monitor connector cover.
  2.  

1989-90 1.6L Engines

See Figures 6 and 7

  1. Start the engine and allow it to warm up to normal operating temperature.
  2.  
  3. Be sure that all of the electrical loads, except for the ignition switch, are OFF. If equipped, ensure that the air conditioning is OFF.
  4.  
  5. Apply the parking brake and place the gearshift in Neutral (manual transmissions) or Park (automatic transmissions).
  6.  
  7. Check the idle speed to ensure that it is 750-850 rpm. If it is not, adjust the idle speed prior to adjusting ignition timing.
  8.  
  9. Turn the ignition switch OFF .
  10.  
  11. Install the inductive timing light according to the manufacturer's instructions. The timing light input lead should always be attached to the No. 1 cylinder spark plug wire.
  12.  
  13. Start the engine and allow it to idle.
  14.  



Click image to see an enlarged view

Fig. Fig. 6: The ignition timing marks are located on a tab attached to the engine


CAUTION
When using the timing light, be sure to keep yourself and all tools away from moving and hot engine components. Do not wear loose clothing when working around a running engine, otherwise personal injury or death may result.

  1. Use the timing light to read the ignition timing by pointing the light at the timing marks (located on the crankshaft pulley and timing belt cover tab) and pulling the light's trigger.
  2.  
  3. If the ignition timing, is not 8 degrees BTDC at 750-850 rpm engine speed, adjust the timing.
  4.  
  5. To adjust the ignition timing, loosen the distributor flange bolt(s) and rotate it until the proper ignition timing is within specifications. Turn the distributor counterclockwise to advance, and clockwise to retard the ignition timing. Tighten the distributor flange bolt(s) securely.
  6.  



Click image to see an enlarged view

Fig. Fig. 7: To adjust the ignition timing, rotate the distributor housing counterclockwise to advance timing and clockwise to retard timing

  1. After adjusting the ignition timing and tightening the distributor flange bolts, recheck the ignition timing to ensure that it did not change while tightening the distributor flange bolts.
  2.  
  3. Shut the engine OFF , then remove the inductive timing light from the vehicle.
  4.  

1991-93 1.6L Engines

  1. Start the engine and allow it to warm up to normal operating temperature.
  2.  
  3. Turn off the engine, turn the ignition switch ON for 5 seconds, then start the engine again and run it at 2000 rpm for 5 minutes. This will ensure that the engine is properly warmed up.
  4.  
  5. Be sure that all of the electrical loads, except for the ignition switch, are OFF. If equipped, ensure that the air conditioning is OFF.
  6.  
  7. Apply the parking brake and place the gearshift in Neutral (manual transmissions) or Park (automatic transmissions).
  8.  
  9. Check the idle speed to ensure that it is 800 rpm. If it is not, adjust the idle speed prior to adjusting ignition timing.
  10.  
  11. Turn the ignition switch OFF .
  12.  
  13. Install the inductive timing light according to the manufacturer's instructions. The timing light input lead should always be attached to the No. 1 cylinder spark plug wire.
  14.  
  15. Remove the cover from the monitor connector, located beside the right-hand head light assembly, and, using a jumper wire, connect terminals C and D . Grounding terminal C to terminal D will fix the ignition timing (prevent the timing from moving).
  16.  
  17. Start the engine and allow it to idle.
  18.  


CAUTION
When using the timing light, be sure to keep yourself and all tools away from moving and hot engine components. Do not wear loose clothing when working around a running engine, otherwise personal injury or death may result.

  1. Use the timing light to read the ignition timing by pointing the light at the timing marks (located on the crankshaft pulley and timing belt cover tab) and pulling the light's trigger.
  2.  

If the timing fluctuates or changes, terminal D is not properly grounded to terminal D .

  1. If the ignition timing, with terminal D properly grounded, is not 7-9 degrees BTDC at 800 rpm engine speed, adjust the timing.
  2.  
  3. To adjust the ignition timing, loosen the distributor flange bolts and rotate it until the proper ignition timing is within specifications. Turn the distributor counterclockwise to advance, and clockwise to retard the ignition timing. Tighten the distributor flange bolts securely.
  4.  
  5. After adjusting the ignition timing and tightening the distributor flange bolts, recheck the ignition timing to ensure that it did not change while tightening the distributor flange bolts.
  6.  
  7. Detach the jumper wire from the monitor connector.
  8.  

With this jumper wire removed, the ignition timing may fluctuate, which is normal.

  1. Observe the ignition timing marks with the timing light while increasing engine speed. The ignition timing should advance as the engine speed increases. If the engine speed does not advance, inspect the TP sensor, the test switch terminal circuit, the engine start signal circuit and PCM.
  2.  


WARNING
Driving the vehicle with the monitor connector terminals grounded will result in catalytic converter damage; be sure to remove the jumper wire prior to driving the vehicle.

  1. Shut the engine OFF , then remove the inductive timing light from the vehicle. Install the monitor connector cover.
  2.  

1994-98 1.6L and 1.8L Engines

See Figures 8 and 9

  1. Start the engine and allow it to warm up to normal operating temperature.
  2.  
  3. Be sure that all of the electrical loads, except for the ignition switch, are OFF. If equipped, ensure that the air conditioning is OFF.
  4.  
  5. Apply the parking brake and place the gearshift in Neutral (manual transmissions) or Park (automatic transmissions).
  6.  
  7. Check the idle speed to ensure that it is within specifications. If it is not, adjust the idle speed prior to adjusting ignition timing.
  8.  
  9. Turn the ignition switch OFF .
  10.  
  11. Install the inductive timing light according to the manufacturer's instructions. The timing light input lead should always be attached to the No. 1 cylinder spark plug wire.
  12.  
  13. Remove the cover from the Duty Check Data Link Connector (DC-DLC), located beside the right-hand headlight assembly (1994-96 models) or next to the battery (1997-98 models), and, using a jumper wire, connect DC-DLC connector cavities 4 and 5 . Grounding cavity 5 to cavity 4 will fix the ignition timing (prevent the timing from moving).
  14.  
  15. Start the engine and allow it to idle.
  16.  



Click image to see an enlarged view

Fig. Fig. 8: Before attempting to inspect the ignition timing, use a small jumper wire to ground the test switch terminal (5) to the ground terminal (4) of the DC-DLC


CAUTION
When using the timing light, be sure to keep yourself and all tools away from moving and hot engine components. Do not wear loose clothing when working around a running engine, otherwise personal injury or death may result.

  1. Use the timing light to read the ignition timing by pointing the light at the timing marks (located on the crankshaft pulley and timing belt cover tab) and pulling the light's trigger.
  2.  

If the timing fluctuates or changes, cavity 5 is not properly grounded to cavity 4 .

  1. If the ignition timing, with terminal 5 properly grounded, is not 4-6 degrees BTDC at 750-850 rpm engine speed, adjust the timing.
  2.  
  3. To adjust the ignition timing, loosen the distributor flange bolts (1.6L engines) or the Camshaft Position (CMP) sensor bolts, and rotate it until the proper ignition timing is within specifications. Turn it counterclockwise to advance, and clockwise to retard the ignition timing. Tighten the distributor flange bolts securely, or tighten the CMP bolts to 133 inch lbs. (15 Nm).
  4.  



Click image to see an enlarged view

Fig. Fig. 9: On 1.8L engines, loosen the CMP sensor bolts and rotate the sensor to adjust ignition timing

  1. After adjusting the ignition timing and tightening the distributor flange bolts, recheck the ignition timing to ensure that it did not change while tightening the distributor flange bolts.
  2.  
  3. Detach the jumper wire from the DC-DLC.
  4.  

With this jumper wire removed, the ignition timing may fluctuate, which is normal.

  1. Observe the ignition timing marks with the timing light while increasing engine speed. The ignition timing should advance as the engine speed increases. If the engine speed does not advance, inspect the TP sensor, the test switch terminal circuit, the engine start signal circuit and PCM.
  2.  


WARNING
Driving the vehicle with the DC-DLC terminals grounded will result in catalytic converter damage; be sure to remove the jumper wire prior to driving the vehicle.

  1. Shut the engine OFF , then remove the inductive timing light from the vehicle. Install the DC-DLC cover.
  2.  

 
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