Idle Speed Control & Throttle Position Sensor: Starion
- Engine coolant temperature should be 185-205°F (85-95°C). Turn lights, cooling fan and accessories off. Place transmission in Neutral or Park. Place steering wheel in straight-ahead position. Loosen accelerator cable.
- Disconnect TPS connector. Connect Harness (MD998459) between separated connecters. See Figure . Connect a voltmeter between Red terminal No. 2 (output) and Black terminal No. 1 (ground).
- Turn ignition on, but do not start engine. Hold switch in "ON" position for 15 seconds or more and ensure ISC servo is set at idle position.NOTE: When ignition switch is turned to "ON" position, ISC servo extends to fast idle position opening. In 15 seconds, it retracts and stops at initial position.
- Turn ignition switch to "LOCK" position. Disconnect ISC servo connector to fix ISC servo at initial position. Connect Test Harness (MD998460) to ISC servo body side harness connector. Ground Red terminal of test harness. The ECU will now operate as if idle switch is on.
- To prevent binding of throttle valve, open throttle valve by hand several times then release with a snap. Loosen fixed servo adjusting screw. See Figure . Start engine and run at idle. Ensure engine speed is 850 RPM. If engine speed is incorrect, tighten fixed servo adjusting screw until speed begins to increase. Loosen servo adjusting screw until engine speed does not drop. Loosen screw and additional one turn.
- Stop engine. Turn ignition switch to "ON" position (engine off). Ensure TPS output voltage is .48-.52 volt. If not to specification, loosen TPS mounting screw and increase voltage by turning TPS clockwise. Decrease voltage by turning TPS counter-clockwise.
- Turn ignition switch to "LOCK" position. Adjust accelerator cable slackness. Remove test harness and reconnect ISC servo and TPS connectors. Start engine and check idle speed. Idle RPM should be 750-950 RPM. Turn ignition switch to "OFF" position. To erase ECU memory, disconnect battery for 5-6 seconds.