Idle Speed Control System
- Run engine at fast idle until coolant temperature is 185-205°F (85-90°C). Turn off engine. Disconnect accelerator cable from throttle lever of injection mixer. Loosen the 2 screws installing the throttle position sensor.
- Turn throttle position sensor fully clockwise. Tighten screws. Turn ignition switch to the "ON" position for more than 15 seconds to set ISC servo. Disconnect ISC servo harness connector. Start engine. Check engine speed and adjust to specification with screw. See Fig 1
.
ENGINE IDLE SPEEDS
| Application |
RPM |
| Colt Turbo |
600 |
| Conquest |
750 |
- Stop engine. Disconnect throttle position sensor harness connector. Connect adapter and digital voltmeter between throttle position sensor connector and harness side connector. See Fig 2
. Turn ignition switch to the ON position but do not start the engine. Read throttle position sensor output voltage.
- Voltage should be .45-.51 volts. If not, loosen throttle position sensor mounting screws, and turn the sensor until output voltage is correct. Apply sealant to the screws and tighten. Fully open the throttle valve, return to original position and check for proper output voltage. Adjust if necessary.
- Remove adapter and voltmeter and reconnect ISC servo harness connector. Make sure curb idle speed is normal. Stop engine. Turn the ignition switch from "OFF" to "ON" position, and after 15 seconds return to "OFF" position. Connect accelerator cable to throttle lever of injection mixer.