Rough, Unstable or Incorrect Idle; Stalling
***UPDATED BY TSB #405489 DATED FEB. 20, 1989Mazda 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
Poor or contaminated fuel Drain fuel tank and fill with clean gasoline
Incorrect air/fuel ratio Check air/fuel ratio,
Refer to Computers and Control Systems
Incorrect fuel pressure See Fuel Pump and Pressure Regulator
Incorrect idle speed Check and adjust
Proceed to Adjustments