Curb Idle Speed Adjustment

1. Disconnect and plug vacuum hose at EGR valve, ESA module, distributor or carburetor, as required.
2. On models equipped with carburetor ground switch, connect jumper wire between switch and ground.
3. On models not equipped with Spark Control Computer (SCC), disconnect and plug vacuum hose from carburetor at heated air temperature sensor and Orifice Spark Advance Control (OSAC) valve, if equipped.
4. On all models, disconnect and plug control hose at canister.
5. Remove PCV valve from cylinder head cover and allow to draw underhood air.
6. Connect tachometer, then start engine and allow to reach normal operating temperature.
7. On models less 1985 6280 carburetor, adjust Solenoid Idle Stop (SIS), if equipped, as follows:
a. On 1983-84 models with A/C, turn on A/C and set blower on low, then disconnect A/C clutch wire.
b. On 1983-84 models less A/C and all 1985-87 models, connect jumper wire between battery positive terminal and the SIS lead wire. Ensure correct jumper wire installation. Applying battery voltage to other than correct wire will damage the wiring harness.
c. On all models, open throttle slightly to allow solenoid plunger to extend.
d. On Holley models, remove adjusting screw and spring from solenoid, then insert 1/8 inch Allen wrench into the solenoid and adjust to correct engine RPM.
e. On Carter models, turn adjusting screw on throttle lever to obtain correct engine RPM.
f. On Rochester models, turn solenoid plunger screw to obtain correct engine RPM.
g. Turn off A/C and reconnect clutch wire or remove jumper, if equipped.
h. Install solenoid screw and spring, if equipped with Holley carburetor.
8. On models with 1985 6280 carburetor, adjust Solenoid Idle Stop (SIS) as follows:
a. Disconnect and ground engine harness electrical connector from oxygen sensor.
b. Allow engine to run at least five minutes, then connect a jumper wire between the battery positive terminal and SIS lead wire. Ensure correct jumper wire installation. Applying battery voltage to other than correct wire will damage the wiring harness.
c. Open throttle slightly to allow solenoid plunger to extend.
d. Remove adjusting screw and spring from solenoid, then insert a 1/8 inch allen wrench into the solenoid and adjust to correct engine RPM.
e. Install screw and spring, then turn in screw until it bottoms out.
9. On 1983-84 models equipped with oxygen sensor feedback carburetors, proceed as follows:
a. Disconnect electrical connector from oxygen sensor and ground connector.
b. Remove and plug vacuum hose at vacuum transducer on SCC, then install suitable vacuum pump to vacuum transducer and apply 16 inches of vacuum.
c. Allow engine to run for two minutes. If idle is not as specified, turn adjusting screw on solenoid to obtain correct RPM.
10. On 1983-84 models not equipped with oxygen sensor feedback carburetors and all 1985-87 model carburetors, proceed as follows:
a. Allow engine to run for one minute.
b. If idle RPM is not as specified, turn idle speed screw to obtain correct RPM.
11. On all models, turn off engine, connect vacuum lines and remove tachometer. Remove jumper wire and connect oxygen sensor electrical connector, if equipped. After step 11 has been completed, idle speed may change slightly. This condition is normal and engine speed should not be readjusted.