Engine: Adjust Throttle Position Sensor (TPS)

Adjust the Idle Position Switch and Throttle Position Sensor (TPS) on a Mitsubishi 3000GT/GTO and Dodge Stealth

TIP: Use a Feeler Gauge to ensure accurate calibration.

1. Disconnect the Throttle Position Sensor's connector

   

   Throttle Position Sensor connector

2. Connect terminal #3 (idle position switch) and terminal #4 (sensor ground) on the Throttle Position Sensor connector using an ohmmeter

   

   Connect terminals #3 and #4 using an ohmmeter

   

3. Insert a 0.65mm thick Feeler Gauge blade between the Fixed SAS and Throttle Lever, as shown in the diagram below:

   

   Insert Feeler Gauge

4. Loosen the Throttle Position Sensor mounting bolts and turn the Throttle Position Sensor's body fully counter-clockwise

   

   Turn TPS's body counter-clockwise

5. Check that there is a complete circuit (known as continuity) across terminals #3 and #4 using the ohmmeter
6. Slowly turn the Throttle Position Sensor clockwise until you find the point at which the circuit is no longer complete across terminals #3 and #4. Then, tighten the Throttle Position Sensor mounting bolts securely

   

   Slowly turn the TPS's body clockwise until circuit breaks

7. Reconnect the Throttle Position Sensor connector

Testing the Throttle Position Sensor

To test the Throttle Position Sensor, you can either use a Multi-use Tester or a Test Harness Set.

1. Plug in your testing device
   • If you are using a Multi-use Tester, connect it to the Diagnosis port in your 3000GT/Stealth now
   • Alternatively, if you are using a Test Harness Set:
     • Disconnect the Throttle Position Sensor connectors and connect the Test Harness Set between the disconnected connectors
     • Connect a Digital Voltmeter between the Throttle Position Sensor's terminal #2 (sensor output) and #4 (sensor ground)

   

   Connect a voltmeter between the TPS's terminal #2 and #4

2. Turn the ignition switch ON (but do not start the engine)
3. Check the Throttle Position Sensor output voltage
   • When using the Multi-use Tester, select item #14 and read the Throttle Position Sensor output voltage
     • The standard value should be between 400 - 1,000 mV
   • If the voltage is out of specification, check the Throttle Position Sensor and its connected harnesses
4. Remove the Feeler Gauge
5. Turn the ignition switch OFF

Checking the Throttle Position Sensor

It is a good idea to check the throttle position sensor to make sure it's functioning correctly.

1. Disconnect the throttle position sensor connector

   

2. Measure rsistance between terminal 4 (sensor Ground) and Terminal 1 (sensor power) Standard value 3.5 - 6.5 Kilo Ohms

   

3. Connect a pointer type ohmmeter between terminal 4(sensor ground) and terminal 2 (sensor output).

   

4. Operate the throttle valve slowly from the idle position to the full open position and check that the resistance changes smoothly in proportion with the throttle valve opening angle.

   

5. If the resistance is out of specification, or fails to change smoothly, replace the throttle position position sensor. Torque to 2.0 Nm (1.5 ft.lbs.)

Checking the Throttle Position Switch

To check the throttle position switch in order to verify that it is functioning correctly:

The Idle postition switch is different from the sensor, The switch is only used to tell the ECU if the the car is at Idle or not.

1. With the accelerator pedal released, check to be sure that the throttle valve lever or the fixed SAS is pushed, if not adjust the fixed SAS
2. Disconnect the throttle sensor connector.

   

3. Check the continuity across the throttle position sneosr connector terminal 4 (sensor ground) and 3 (idle position switch)

Additional Factory Service Manual Details (91-94 Models)