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 >> Deceleration Control Valve >> 1974 Models
April 5, 2026: LEMON Manuals is launched! Read the announcement.

1974 Models

  1. Disconnect hose from air cleaner-to-deceleration control valve (at valve). See Fig 1. With engine at idle, ensure there is no vacuum at control valve port. Stop engine.
  2. Disconnect hose from air cleaner-to-coasting valve and plug vacuum port of deceleration control valve. With engine at idle, disconnect solenoid wire from anti-afterburn valve. Hold hand over suction hose of anti-afterburn valve, no suction should be felt.
  3. Stop engine. Reconnect solenoid wire and hose to deceleration control valve. Disconnect hose from intake manifold at anti-afterburn valve and plug air suction port.
  4. With engine at idle, disconnect wire from coasting valve solenoid. Hold hand over opening of air suction hose of deceleration control valve. Vacuum should be felt. Reconnect all hose and wires.
Fig 1: 1974 Deceleration Control Valve
G09310008Courtesy of MAZDA MOTORS CORP.