Federal Civic Hatchback with 1500 Eng. & Man. Trans. Only (Engine Hot)

1. Disconnect lower hose at throttle control valve and install vacuum pump to hose.
2. With ignition key on, draw vacuum. No vacuum should hold. If there is vacuum, check operation of thermosensor and throttle opener solenoid valve B. Repair or replace as necessary and retest.
3. If there is no vacuum, draw vacuum with engine at 2500 RPM. If there is vacuum, test is complete. If there is no vacuum, check for voltage at blue wire of connector for throttle opener solenoid valve B. If there is voltage, replace valve B and retest. If there is no voltage, replace engine RPM sensor.

Fig 1: Throttle Control System Diagram (Federal Civic Hatchback with 1500 Eng. & Man. Trans.)

Courtesy of AMERICAN HONDA MOTOR CO., INC.