CRX (Hot Engine)

NOTE: If dashpot diaphragm in throttle controller is damaged or vacuum to dashpot diaphragm is blocked or leaks, correct idle speed cannot be obtained. Idle speed will be excessively high after engine reaches normal operating temperature.

Connect tachometer. Start engine and run until normal operating temperature is reached (cooling fan comes on). Ensure idle speed is not excessively high. If idle speed is within specification, proceed to step 5). If idle speed is high, disconnect vacuum hose No. 6 from throttle controller and check for vacuum at hose.
If there is vacuum, replace throttle controller and retest. If there is no vacuum on all models except Federal HF, check vacuum hose No. 6 for leaks or blockage. Repair or replace as necessary and retest.
On Federal HF models, check for voltage between dashpot control solenoid valve Red/Yellow and Black wire terminals (at No. 1 control box connectors). If there is no voltage, check vacuum hose No. 6 for leaks or blockage. If hose is okay, replace dashpot control solenoid valve and retest.
If there is voltage, check clutch switch, neutral switch and speed sensor. Check for voltage at control unit connector (White/Yellow wire). Check for voltage at control unit connector (Black/Yellow wire) with ignition on. If there is no voltage, check wiring. Check Black and Brown/Black wires for continuity between control unit and ground. There should be continuity.
With engine idling, disconnect No. 6 vacuum hose from throttle controller. Engine speed should increase to 1400-2000 RPM. If engine speed does not increase to specification, turn throttle controller adjusting screw to adjust. If RPM does not change, check throttle controller linkage for free movement. If linkage is okay, replace throttle controller and retest.