Surges at Steady Speed

***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: Engine power variation under steady throttle or cruise. Feels like the car speeds up and slows down with no change in accelerator pedal.

POSSIBLE CAUSE ACTION

Fuel delivery volume insufficient Check fuel pump and fuel filter

Incorrect fuel pressure Check Fuel Pressure Regulator

Poor or contaminated fuel Drain fuel tank and add clean gasoline

Dirty fuel filter Replace fuel filter

Lean operating condition Check closed loop computer operation.

Vacuum leak Inspect vacuum hoses for
proper routing and damaged lines
Check intake manifold and throttle chamber