Hot Engine

Warm engine to normal operating temperature. Do not manually open throttle. If speed drops below 1400 RPM as engine warms, adjust fast idle speed.
NOTE: When engine warms up, speed should drop below 1400 RPM as unloader pulls internal choke linkage off fast idle cam.
If fast idle does not drop below 1400 RPM, disconnect 2 unloader hoses and check for vacuum. If vacuum is present, check unloader diaphragm for leaks and/or blockage.
Remove choke cover and check for free movement of unloader rod. Repair or replace as necessary and retest. If no vacuum is present at the inner fitting, check for vacuum at choke opener and thermovalve "B".
On all models except Federal CRX HF, if there is no vacuum at outer fitting, check thermovalve "A". Repair or replace as necessary. If there was no vacuum at outer fitting on Federal CRX HF models, check for voltage at unloader solenoid valve in control box No. 1 between Red/Green (+) and Black (-) wires.
If there is no voltage, replace unloader solenoid valve and retest. If there is voltage at unloader solenoid valve, check intake air temperature sensor and speed sensor.
Check for voltage at control unit connector White/Yellow wire. Turn ignition on. Check for voltage at control unit connector Black/Yellow wire. If there is no voltage, check wiring. Check Black and Black/Brown wires for continuity between control unit and ground. There should be continuity.