LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 1978 >> Cosmo Automatic Trans >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Exhaust Emissions System - Deceleration Control System - Rotary Engines >> Testing >> Idle Switch >> 1975-78 Models
April 5, 2026: LEMON Manuals is launched! Read the announcement.

1975-78 Models

  1. Disconnect idle switch. Check continuity between switch terminals. Continuity should be as specified in IDLE SWITCH CONTINUITY table.
  2. If not, remove limiter cap on switch. Connect tachometer to engine. Connect ohmmeter to switch terminals No. 1 and 3. See Fig 5. With automatic transmission in Neutral, start engine.
    Fig 1: 1977-78 Deceleration Control System
    G09310011Courtesy of MAZDA MOTORS CORP.
    Fig 2: 1979 Anti-Afterburn Solenoid Test
    G09310012Courtesy of MAZDA MOTORS CORP.
  3. Slowly increase engine speed. Turn adjusting screw until continuity is broken between terminals No. 1 and 3 at RPM specified in IDLE SWITCH CONTINUITY table. Replace switch if it does not operate within specifications.
    IDLE SWITCH CONTINUITY

    Engine RPM Continuity Between Terminals No Continuity Between Terminals
    Idle 1 & 3 1 & 2
    950-1050 (Man. Trans.) 1 & 2 1 & 3
    1150-1250 (Auto. Trans.) 1 & 2 1 & 3
    Fig 3: 1979 Coasting Valve Test
    G09310013Courtesy of MAZDA MOTORS CORP.
    Fig 4: 1978-79 Dashpot Delay Valve Test
    G09310014Courtesy of MAZDA MOTORS CORP.
    Fig 5: Idle Switch Continuity Test
    G09310015Courtesy of MAZDA MOTORS CORP.
scientia non olet · About LEMON Manuals