Idle Speed: Adjustments

Fig. 1 Fuel injection system components.:

Fig. 2 Fuel injection diagnostic socket terminal location.:

FUEGO TURBO

During the following adjustment, a voltmeter with a minimum input impedance of 20,000 ohms per volt must be used.

1. Start engine and allow to reach normal operating temperature.
2. Adjust throttle plate bypass screw, Fig. 1, until idle speed is as specified in Tune Up Specifications.
3. Disconnect oxygen sensor electrical lead.
4. Connect voltmeter between diagnostic socket terminals 2 and 8, Fig. 2. Voltage should read approximately 6.5 volts.
5. Reconnect oxygen sensor electrical lead and note voltage. Voltage should be the same plus or minus .5 volts as recorded in previous step. If not, turn airflow sensor bypass screw, Fig. 1, as necessary until specified voltage is obtained. It may be necessary to operate engine at approximately 2000 RPM for a few minutes to allow oxygen sensor to warm up. Perform adjustment within 30 seconds after allowing engine to return to idle speed to avoid inaccurate readings.
6. Check idle speed and adjust as necessary. The airflow sensor bypass screw is pre-adjusted and sealed at the factory. If air/fuel mixture requires adjustment, remove tamper-proof concealment plug as outlined in ``Gasoline Fuel Injection.''

Fig. 3 Diagnostic connectors.:

ALLIANCE, ENCORE, FUEGO & SPORTWAGON W/MULTI-POINT FUEL INJECTION

During the following adjustment, a voltmeter with a minimum input impedance of 20,000 ohms per volt must be used.

1. Start engine and allow to reach normal operating temperature.
2. Connect tachometer to diagnostic test terminals D1-1 and D1-3, Fig. 3.
3. Turn off all accessories, then allow electric cooling fan to cycle on and off.
4. With transmission in Drive (manual transmission in Neutral), turn idle speed adjustment bypass screw inward or outward to adjust curb idle speed to specifications.
5. Remove tamper proof plug to gain access to air/fuel mixture adjusting screw. Screw is located on top of air flow meter housing. Refer to ``Gasoline Fuel Injection'' for tamper proof concealment plug removal procedure.
6. Disconnect oxygen sensor wire connector, then connect voltmeter to diagnostic terminals D2-2 and D2-7, Fig. 3. While performing the following test on Alliance, Encore & GTA models, the fuel pressure regulator vacuum source must be connected.
7. Observe voltmeter. Voltmeter should read between 6 and 7 volts.
8. Reconnect oxygen sensor wire connector. Adjust air/fuel mixture screw to obtain voltage noted in Step 7 plus or minus .5 volts.
9. Readjust curb idle speed, if necessary.
10. Install new tamperproof plug.