Coasting Richer System

Run engine at idle speed. Using a voltmeter with negative lead to ground, backprobe terminal "H" (Brown/Black wire) of solenoid valve connector. See Fig 1 .
Increase engine speed to 3000 RPM and lift idle switch arm. See Fig 2 . Verify voltmeter indicates appropriate voltage according to RPM. See COASTING RICHER SYSTEM RPM/VOLTAGE TABLE .

Fig 1: Checking Coasting Richer Solenoid Valve

Courtesy of MAZDA MOTORS CORP.

Fig 2: Locating Idle Switch Arm

Courtesy of MAZDA MOTORS CORP.