Mitsubishi Pick-ups and Montero 1983-1995 Repair Guide

General Information

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On all vehicles equipped with adjustable ignition timing and an adjustable idle speed the two processes of adjusting the idle speed and the ignition timing are very closely related and affect each other closely. When doing either of these adjustments, it is usually necessary to adjust each in a back and forth manner since they affect each other. For example, if the ignition timing is adjusted the idle speed could increase past what is recommended. This in turn could affect actual ignition timing during normal use of the vehicle, which would affect the vehicle's driveability. Therefore, the idle speed would have to be adjusted, which could in turn affect the ignition timing. Eventually, after adjusting each back and forth a few times to reach the desired specifications, they will meet the specifications of both simultaneously. Most often they need only to be adjusted a few times before both are correct.

INSPECTION AND ADJUSTMENT



2.0L and 2.6L Engines

See Figures 1 and 2

  1. Drive the vehicle until the engine is hot; the temperature gauge indicates normal operating temperature.
  2.  



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Fig. Fig. 1: Boost sensor location

  1. Leave the engine idling, apply the handbrake and put the transmission in Neutral (manual) or Park (automatic). Turn off all accessories.
  2.  
  3. Install a tachometer, connecting the red lead to the (-) terminal of the coil and the black lead to a clean ground (the battery negative terminal works well) or as otherwise detailed by the manufacturer of the tachometer. Verify that the engine idle speed is correct. If not adjust it. See the idle adjustment procedure later in this section.
  4.  
  5. Stop the engine and connect a timing light according to the manufacturer's instructions.
  6.  
  7. If the front pulley and timing marks are dirty, wipe them clean with a rag. If they are hard to see, you might want to put a small drop of white paint on both the timing scale and groove in the pulley. You may have to turn the engine over using a wrench on the bolt in the front of the crankshaft pulley to do this. Check the timing specifications on the Tune-up Charts or on the engine compartment sticker. Make sure all wires are clear of any rotating parts and the light is in a secure place. Make sure you haven't left any rags or tools near the engine.
  8.  

If the tune-up specifications on the Vehicle Emission Control Information sticker in the engine compartment of your Mitsubishi disagree with the Tune-Up Specifications chart in this section, the figures on the sticker must be used. The sticker often reflects changes made during the production run.

  1. If you are performing the timing procedure at high altitudes (more than 3,900 ft. above sea level), disconnect the pressure sensor electrical connector (if so equipped), located just across from the distributor wires at the top of the cap, before stopping the engine. The sensor is a box bolted to the fender with a vacuum hose connected to the bottom of the unit. Also disconnect the vacuum hose with the white stripes that is connected to the lowermost portion of the distributor vacuum advance, if so equipped. Plug the end of the hose.
  2.  
  3. Start the engine and allow it to idle. Point the timing light at the mark on the front cover and read the timing by noting the position of the groove in the front pulley in relation to the timing mark or scale on the front cover. If the timing is incorrect, loosen the distributor mounting bolt or nut. Turn the distributor slightly clockwise to retard the timing or counterclockwise to advance it (advance means turning to a setting representing more degrees before top dead center). When the timing is correct, tighten the distributor mounting bolt and verify that the setting has not changed. If necessary, readjust the position of the distributor until the setting is correct after the bolt or nut is tight.
  4.  



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Fig. Fig. 2: Rotate the distributor to adjust the timing

  1. If so equipped, reconnect the white striped vacuum hose or the pressure sensor connector. Recheck the timing. The timing should advance at high altitudes.
  2.  
  3. Turn the engine off, disconnect the timing light and tachometer.
  4.  

2.4L and 3.0L (12 Valve) Engines

See Figures 3, 4 and 5

For the timing adjustment procedure on these vehicles, you will need a jumper wire approximately two feet long with alligator clips on both ends. You will also need a paper clip. Make sure that you have these items on hand before attempting to check the timing.

  1. Drive the vehicle until the engine is hot; the temperature gauge indicates normal operating temperature. Apply the handbrake and put the transmission in Neutral (manual) or Park (automatic). Turn off all accessories.
  2.  
  3. Stop the engine and connect a timing light in accordance with the manufacturer's instructions.
  4.  



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Fig. Fig. 3: Engine speed detection connector-2.4L and 3.0L (12 valve) Engines



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Fig. Fig. 4: Tachometer connector terminal and correct application of the paper clip



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Fig. Fig. 5: Ignition timing adjustment terminal-2.4L and 3.0L (12 valve) Engines

  1. Trace the wire that runs from the primary side of the ignition coil to the noise filter. You will find a single terminal harness connector between these two points or locate the engine speed detection connector-refer to the illustrations for location on your model. Insert a paper clip through the connector on either the female or the male side where the wire enters the connector, do not separate the connector. The paper clip must make full contact with the surface of the connector terminal and must be inserted at the proper angle or you will not be able to get it out.
  2.  
  3. Once the paper clip is in place, connect a tachometer to it.
  4.  
  5. Start the engine and check the idle speed. Adjust as necessary.
  6.  
  7. Stop the engine and turn the ignition switch OFF .
  8.  
  9. Connect a lead wire with alligator clips to the ignition adjustment terminal (refer to the illustration), and ground it.
  10.  
  11. Start the engine and allow it to idle.
  12.  
  13. Illuminate the timing marks on the crankshaft pulley with the timing light. Basic ignition timing should be between 3-7° BTDC.
  14.  
  15. If the timing is not as specified, loosen the distributor mounting nut and turn the distributor to the right to retard the timing or to the left to advance it.
  16.  
  17. Once the timing is set to specifications, tighten the mounting nut, being careful not to disturb the distributor.
  18.  
  19. Stop the engine and disconnect the jumper wire from the ignition timing connector and ground.
  20.  
  21. Start the engine and run it at idle speed.
  22.  

If the tune-up specifications on the Vehicle Emission Control Information sticker in the engine compartment of your Mitsubishi disagree with the specifications in this section, the figures on the sticker must be used. The sticker often reflects changes made during the production run.

  1. Check the timing again with the timing light. The timing should be 8° BTDC for the 2.4L and 15° BTDC for the 3.0L (12 valve) engines. This is called actual ignition timing. If the timing is not exactly 8° or 15°, do not be alarmed. This value may vary depending on what mode the computer is in at the time the base adjustment was made. If you do not see a change, check the base timing again. If the base timing is correct, the engine is in time and no further adjustment is necessary.
  2.  

The ignition timing may vary from the specification even under normal operating conditions and is automatically further advanced at higher altitudes.

3.0L (24 Valve) and 3.5L Engines

See Figures 6, 7 and 8

For the timing adjustment procedure on these vehicles, you will need a jumper wire approximately two feet long with alligator clips on both ends. You will also need a paper clip. Make sure that you have these items on hand before attempting to check the timing.

  1. Drive the vehicle until the engine is hot; the temperature gauge indicates normal operating temperature. Apply the handbrake and put the transmission in Neutral (manual) or Park (automatic). Turn off all accessories.
  2.  



Click image to see an enlarged view

Fig. Fig. 6: Engine speed detection connector-3.0L (24 valve) and 3.5L Engines



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Fig. Fig. 7: Ignition timing adjustment terminal-3.0L (24 valve) and 3.5L Engines

  1. Stop the engine and connect a timing light in accordance with the manufacturer's instructions.
  2.  
  3. Trace the wire that runs from the primary side of the ignition coil to the noise filter. You will find a single terminal harness connector between these two points or locate the engine speed detection connector-refer to the illustrations for location on your model. Insert a paper clip through the connector on either the female or the male side where the wire enters the connector. Do not disconnect the two wires. The paper clip must make full contact with the surface of the connector terminal and must be inserted at the proper angle or you will not be able to get it out.
  4.  



Click image to see an enlarged view

Fig. Fig. 8: The correct location for inserting the paper clip-2.4L, 3.0L and 3.5L models

  1. Once the paper clip is in place, connect a tachometer to it.
  2.  
  3. Start the engine and check the idle speed, which should be between 600-800 rpm. Adjust as necessary.
  4.  

The reading on the tachometer indicates1/3of the actual engine speed. In other words, the actual engine speed is three times the indication on the tachometer.

  1. Stop the engine and turn the ignition switch OFF .
  2.  
  3. Disconnect the waterproof female connector from the ignition timing adjustment connector (brown).
  4.  
  5. Use a jumper wire to ground the ignition timing adjustment terminal.
  6.  

Grounding this terminal sets the engine to the basic ignition timing.

  1. Start the engine and run it at idle speed.
  2.  
  3. Illuminate the timing marks on the crankshaft pulley with the timing light. Basic ignition timing should be 2-8° BTDC.
  4.  
  5. If the ignition is not within the standard value range, refer to the crank angle sensor adjustment in Emission Controls .
  6.  
  7. Stop the engine and disconnect the jumper wire from the ignition timing connector and ground.
  8.  
  9. Start the engine and run it at idle speed.
  10.  

If the tune-up specifications on the Vehicle Emission Control Information sticker in the engine compartment of your Mitsubishi disagree with the specifications in this section, the figures on the sticker must be used. The sticker often reflects changes made during the production run.

  1. Check the timing again with the timing light. The timing should be 15° BTDC for the 3.0L (24 valve) and 3.5L engines. This is called actual ignition timing. If the timing is not exactly 15° BTDC, do not be alarmed. This value may vary depending on what mode the computer is in at the time the base adjustment was made. If you do not see a change, check the base timing again. If the base timing is correct, the engine is in time and no further adjustment is necessary.
  2.  

The ignition timing may vary from the specification even under normal operating conditions and is automatically further advanced at higher altitudes.

 
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