Rough, Unstable or Incorrect Idle; Stalling

***UPDATED BY TSB #405489 DATED FEB. 20, 1989

Mazda recommends the use of UNLEADED REGULAR gasoline only, in all vehicles not equipped with a turbocharger, unless otherwise specified. Do not use, or recommend for use, any higher octane fuels. Starting, idle, and driveability problems may result. See factory Technical Service Bulletin #405489, titled "USE OF REGULAR UNLEADED GASOLINE".

Definition: The engine runs unevenly at idle. If bad enough, the vehicle may shake. Also, the idle may vary in rpm. Either condition may be severe enough to cause stalling. Engine idles at incorrect speed.

POSSIBLE CAUSE ACTION

Unmeasured air entering intake system (vacuum leak or Repair air leak
air leak between air flow sensor and throttle valve)

Poor or contaminated fuel Drain fuel tank and fill with clean gasoline

Incorrect air/fuel ratio Check closed loop computer operation.

Incorrect fuel pressure Check Fuel Pressure Regulator

Incorrect base idle speed Check and adjust if necessary.