Curb Idle Speed Adjustment

Fig. 3 Adjusting curb idle speed:

EXC. 1985-86 COLT VISTA W/AUTO. TRANS.
1. Ensure all lights and accessories are in Off position.
2. Disconnect electrical connector from electric fan motor, if equipped.
3. Position transmission or transaxle shift lever in Neutral.
4. Start and operate engine until engine coolant reaches normal operating temperature, then check and adjust ignition timing to specifications.
5. Increase engine speed to 2000 to 3000 RPM for 5 seconds or more, then decrease engine speed to idle for approximately 2 minutes.
6. Install a suitable tachometer onto engine as per manufacturer's instructions.
7. Check curb idle speed. If curb idle speed is not within specifications, turn idle speed adjusting screw ``SAS 1'' until specified curb idle speed is obtained, Fig. 3.

Fig. 4 Adjusting curb idle speed. 1985-86 Colt Vista w/Auto. Trans.:

1985-86 COLT VISTA W/AUTO. TRANS.
On these models, curb idle speed is controlled by the idle speed control (ISC) servo. When adjustment of the idle speed is necessary, the ISC system should be checked using the following procedure.
1. Ensure all lights and accessories are in Off position.
2. Disconnect electrical connector from electric fan motor and shift transaxle to Neutral or Drive.
3. Remove concealment plug as described under ``Concealment Plug Removal'' in ``Carburetor.''
4. Start and run engine until normal operating temperature is reached, then stop engine.
5. Loosen accelerator cable tension.
6. Turn ignition switch on for a minimum of 18 seconds, then turn switch off and disconnect electrical connectors from ISC actuator and oxygen sensor.
7. Start and race engine 2 or 3 times at 2000-3000 RPM, then return to idle for 30 seconds and adjust mixture adjusting screw to obtain a CO reading of .1%-.3%.
8. Adjust engine speed to 700 RPM using TPS adjusting screw.
9. Tighten SAS, Fig. 4, until engine speed increases, then loosen SAS until the point just before speed decreases. From this position, loosen SAS an additional 2/3 turn.
10. Race engine several times and check that engine speed and CO are still within specifications.
11. Adjust accelerator cable tension to provide proper contact with the idle switch.
12. Reconnect ISC actuator and oxygen sensor electrical connectors.