Mitsubishi Pick-ups and Montero 1983-1995 Repair Guide

Vacuum System Components

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TESTING



Pick-up
GENERAL OPERATION

See Figure 1

  1. Check the vacuum circuit for leaks or clogging.
  2.  
  3. Unplug the vacuum pump wiring harness connector.
  4.  
  5. Disconnect the check valve vacuum hose at the actuator and vacuum pump side, and connect a vacuum gauge in its place.
  6.  
  7. Connect a 12 volt battery's positive (+) terminal to the connector L terminal (power side) and the battery's negative (-) terminal to connector B terminal (GND side) and operate the motor to check the generated negative pressure (vacuum).
  8.  



Click image to see an enlarged view

Fig. Fig. 1: Attach a vacuum gauge to the pump to check the vacuum created-1988-95 Pick-up

  1. The standard value of the negative pressure produced is 5.9 in. Hg/min. (9.3 kPa/min.) or more.
  2.  
  3. After the release of the negative pressure, connect the battery again to generate negative pressure. Check that the disconnection of the battery to stop the motor does not cause a sudden loss of vacuum.
  4.  
  5. If the pump does not meet the previously stated standards, it will need to be replaced by a new unit.
  6.  

VACUUM SWITCH
  1. Unplug the wiring connector from the vacuum switch.
  2.  
  3. Use a hand vacuum pump, connected to the negative pressure port of the switch, to apply a vacuum.
  4.  
  5. Check for continuity between the switch terminals.
  6.  
  7. Check that there is no sudden drop of vacuum.
  8.  
  9. If the switch fails either of these tests, replace it with a new one.
  10.  

VACUUM PUMP RELAY

See Figure 2

  1. Unplug the wiring harness connector from the vacuum pump relay.
  2.  
  3. Hook the battery (12 volt) positive terminal to terminal 1 (green wire) of the relay and the negative terminal to terminal 2 (blue and red wire). This will energize the relay coil.
  4.  
  5. Check for continuity between terminals 3 and 4 when the coil is energized. There should be continuity present ( approximately. 0 ohms).
  6.  



Click image to see an enlarged view

Fig. Fig. 2: Connect a 12 volt battery's positive terminal to terminal 1 (green) and its negative terminal to terminal 2 (blue with red) to energize the relay coil-1988-95 Pick-ups

  1. Disconnect the battery from the relay (this will de-energize the coil) and check terminals 3 and 4 again. There should be no continuity present.
  2.  
  3. Check the continuity across terminals 1 and 2 with the coil de-energized. There should be approximately 70 ohms present.
  4.  
  5. If the relay fails any of the preceding tests, replace it with a new unit.
  6.  

VACUUM CHECK VALVE
  1. Remove the check valve from its vacuum lines.
  2.  
  3. Blow into nipple B and check that air blows out from nipple A.
  4.  
  5. If the air does not blow through, replace the check valve with a new unit.
  6.  
  7. Install the check valve back between the vacuum lines. Make certain that the arrow on the check valve points toward the inlet manifold side.
  8.  

1992-95 Montero
SOLENOID VALVE

See Figure 3

A control valve and release valve are contained within the solenoid valve.

  1. Unplug the wiring harness connector from the cruise vacuum pump.
  2.  
  3. Measure the resistance value between terminals 1 and 2, and also between terminals 1 and 3. The standard value should be 50-60 ohms.
  4.  
  5. Check that the solenoid valve makes an operating noise when battery voltage is applied to terminals 1 and 2, as well as to terminals 1 and 3.
  6.  
  7. If there is a malfunction of the solenoid valve, replace the cruise vacuum pump assembly.
  8.  



Click image to see an enlarged view

Fig. Fig. 3: Measure the solenoid valve resistance between terminals 1 and 2, and also between terminals 1 and 3-1992-95 Monteros

MOTOR
  1. Unplug the wiring harness to the cruise vacuum pump.
  2.  
  3. Check that the motor revolves when battery positive voltage is applied between terminals 1 and 4.
  4.  
  5. If the motor does not operate, replace it with a new unit.
  6.  

REMOVAL & INSTALLATION



Pick-up

See Figure 4

  1. Disconnect the negative battery cable from the battery.
  2.  
  3. Remove the column switch-refer to the procedures in this section.
  4.  
  5. Remove the instrument cluster/combination meter-refer to the procedures in this section.
  6.  
  7. Disconnect the vacuum hoses and remove the check valve.
  8.  
  9. Disconnect the wiring harness plug and the vacuum hose from the vacuum switch and remove it.
  10.  
  11. Unplug the wiring harness connector from the vacuum pump relay. Unbolt the retaining nut and remove it from the bracket.
  12.  
  13. Unplug the engine compartment wiring harness from the actuator and vacuum pump connectors.
  14.  
  15. Remove the retaining screws and remove the cover from over the actuator assembly.
  16.  
  17. Disconnect accelerator cables A and B from the throttle body.
  18.  
  19. Remove the actuator assembly and the throttle body linkage from the intake manifold plenum.
  20.  
  21. Remove the vacuum pump from the throttle body linkage bracket.
  22.  
  23. Disconnect the wiring from the stop light/brake switch and the clutch pedal switch, then remove these two switches from the pedal assemblies.
  24.  
  25. Remove the vehicle speed sensor (incorporated into the speedometer) and the auto-cruise control switch (integrated into the column switch) from their respective assemblies.
  26.  



Click image to see an enlarged view

Fig. Fig. 4: Auto-cruise control system removal and installation components-1988-95 Pick-ups

  1. To install, install the vehicle speed sensor and the auto-cruise control switch into their respective assemblies.
  2.  
  3. Install the stop light/brake switch and the clutch pedal switch into the pedal assemblies and hook the wiring back up to them.
  4.  
  5. Mount the vacuum pump back to the throttle body linkage bracket.
  6.  
  7. Install the actuator and throttle body linkage assembly onto the intake manifold plenum with the mounting bolts.
  8.  
  9. Install the accelerator cables A and B. Tighten their retaining nuts to 6-8 ft. lbs. (8-11 Nm) and their retaining bolts to 4-6 ft. lbs. (6-8 Nm). Refer to Fuel System for the accelerator cable adjustments.
  10.  
  11. Set the cover over the actuator and secure it with the mounting screws.
  12.  
  13. Plug the engine compartment wiring harness back to the actuator and vacuum pump connectors.
  14.  
  15. Attach the vacuum pump relay and vacuum switch back onto the mounting bracket. Hook the wiring harness connectors back together and install the vacuum hoses.
  16.  
  17. Install the check valve between the two vacuum lines. Make certain that the arrow on the check valve points toward the inlet manifold.
  18.  
  19. Install the combination meter/instrument cluster and the column switch.
  20.  
  21. Adjust the brake pedal switch-refer to Brake Systems for this procedure.
  22.  
  23. Connect the negative battery cable to the battery.
  24.  
  25. Take the vehicle out for a drive and road-test the cruise control system.
  26.  

1988-91 Montero

See Figure 5

  1. Disconnect the negative battery cable from the battery.
  2.  
  3. Unscrew the retaining bolt and remove the protector plate from the actuator.
  4.  
  5. Loosen the two accelerator cables' adjusting nuts, then unfasten the actuator side inner cables from the actuator.
  6.  
  7. Unplug the actuator wiring harness connector.
  8.  
  9. Remove the three mounting nuts, then remove the actuator assembly itself from the mounting bracket. Make sure to retain the mounting nuts, washers, spacers, and rubber grommets for reassembly.
  10.  
  11. Unplug the wiring harness connectors to the accelerator, stop light, clutch and inhibitor switches. Remove these switches from their respective assemblies.
  12.  
  13. Remove the combination meter, by using the procedures found in this section. Remove the vehicle speed sensor, which is attached to the speedometer.
  14.  
  15. The auto-cruise control switch is an integral part of the column switch, remove this switch-refer to the instructions in this section.
  16.  
  17. To remove the control unit, remove the front rail cover and the front door opening trim.
  18.  
  19. Remove the cowl side trim, then remove the auto-cruise control unit.
  20.  



Click image to see an enlarged view

Fig. Fig. 5: Auto-cruise control system removal and installation components-1988-91 Monteros

  1. To install, mount the auto-cruise control unit and install the cowl side trim.
  2.  
  3. Install the door opening trim and secure the front rail cover in place with the mounting screws and retainers.
  4.  
  5. Install all of the inside switches onto their respective assemblies. Install the combination meter and column switch.
  6.  
  7. Set the rubber grommets onto the actuator bracket's studs, then set the actuator on the studs. Secure it in place with the washers and nuts.
  8.  
  9. Plug the harness connectors back together.
  10.  
  11. Install the accelerator cables and adjust them-refer to Fuel System for accelerator cable adjustment procedures.
  12.  
  13. Tighten the accelerator cable adjuster-nut locking nuts to 6-8 ft. lbs. (8-11 Nm).
  14.  
  15. Mount the protector plate on the actuator with the retaining bolt.
  16.  
  17. Connect the negative battery cable to the battery.
  18.  

1992-95 Montero

See Figures 6 and 7

  1. Disconnect the negative battery cable from the battery.
  2.  
  3. Unbolt the retaining bolt and remove the link protector from the intermediate link.
  4.  
  5. Disconnect the accelerator cable, the throttle cable and the cruise control cable from the intermediate link.
  6.  
  7. Remove the four nuts holding the intermediate link to the link bracket, then pull the link off of the bracket.
  8.  
  9. Unscrew the one retaining bolt on the link bracket. Remove the bracket.
  10.  
  11. Unplug the wiring harness connector from the vacuum pump.
  12.  
  13. Remove the vacuum pump vacuum hoses and remove the pump from the pump bracket.
  14.  
  15. Remove the three nuts holding the vacuum pump bracket onto the actuator bracket, then pull the bracket off.
  16.  
  17. Disconnect the vacuum hose to the actuator and remove the actuator from the actuator bracket.
  18.  



Click image to see an enlarged view

Fig. Fig. 6: Cruise control link and actuator removal and installation components-1992-95 Monteros



Click image to see an enlarged view

Fig. Fig. 7: Cruise control system sensor and switch removal and installation components-1992-95 Monteros

  1. To install, mount the actuator onto the actuator bracket.
  2.  
  3. Mount the vacuum pump bracket onto the actuator bracket with the three nuts and washers.
  4.  
  5. Install the vacuum pump to the vacuum pump bracket. Connect the actuator and the vacuum pump with the vacuum hose.
  6.  
  7. Plug the wiring harness connectors back together.
  8.  
  9. Mount the link bracket with the one retaining bolt.
  10.  
  11. Using the four nuts, secure the intermediate link to the link bracket.
  12.  
  13. Attach the accelerator cable, the throttle cable, and the cruise control cable to the intermediate link.
  14.  
  15. Adjust the accelerator cable, the throttle cable, and the cruise control cable. Check to see if there is any deflection in the inner cables of the accelerator cable, cruise control cable and throttle cable. If there is excessive deflection or no play in an inner cable, loosen the adjusting bolts and nuts to release each link from the throttle lever (do not remove the adjusting bolts or nuts).
    1. Accelerator cable: while holding link (C) so that it is touching the stopper, adjust the play of the accelerator cable with the adjusting nut so that the cable play is 0-0.04 in. (0-1mm) for non-California vehicles or 0.08-0.12 in. (2-3mm) for California models. After adjusting, secure the cable with the lock nut.
    2.  
    3. Throttle cable: while holding link (B) so that it is touching link (C), adjust the play of the accelerator cable with the adjusting nut and adjusting bolts (throttle lever side) so that the cable play is 0.04-0.08 in. (1-2mm). After adjusting, secure the cable with the lock nut.
    4.  
    5. Cruise control cable: while holding link (A) so that it is touching link (B), adjust the play of the accelerator cable with the adjusting nut so that the cable play is 0.04-0.08 in. (1-2mm). After adjusting, secure the cable with the lock nut.
    6.  

  16.  
  17. Replace the intermediate link unit's cover.
  18.  
  19. Connect the negative battery cable to the battery.
  20.  

 
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