Engine: Adjust Throttle Position Sensor (TPS)

How to Adjust the Idle Position Switch and Throttle Position Sensor (TPS) on a 3000GT/Stealth

TIP: It is suggested that you use a Feeler Gauge to ensure accurate calibration.

1. Disconnect the Throttle Position Sensor's connector

   

2. On the Throttle Position Sensor, connect terminal #3 (idle position switch) and terminal #4 (sensor ground) using an ohmmeter (using a set of jumper wires)

   

   

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

   

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

   

5. Check that there is continuity (a complete circuit) across terminals #3 and #4 using the ohmmeter
6. Slowly turn the Throttle Position Sensor clockwise until you find a point at which the circuit breaks across terminals #3 and #4. Then, tighten the throttle position sensor mounting bolt securely

   

7. Reconnect the Throttle Position Sensor connector
8. When using the multi-use tester, connect it to the diagnosis connector.
9. When not using the multi-use tester, proceed as follows:
   • Disconnect the throttle position sensor connectors and connect the special tool, Test Harness Set, between the disconnected connectors.
   • Connect a digital voltmeter between the throttle position sensor terminal 2 (sensor output) and teminal 4 (sensor ground).

   

10. Turn the ignition switch ON (but do not start the engine).
11. Check the throttle position sensor output voltage. When using the multi-use tester, select item No. 14 and read the throttle position sensor output voltage. Standard value: 400 - 1,000 mV
12. If the voltage is out of specification, check the throttle position sensor and associated harnesses.
13. Remove the feeler gauge.
14. 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)