Surges at Steady Speed

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

Insufficient fuel capacity ^ Check fuel capacity, refer to FUEL SYSTEM DIAGNOSIS

Faulty fuel pressure regulator ^ Check fuel pressure, refer to FUEL SYSTEM DIAGNOSIS

Contaminated fuel ^ Check for water or excessive alcohol in fuel
^ Drain fuel tank and add clean fuel

Dirty fuel filter ^ Replace fuel filter

Lean operating condition ^ Check computer controls, refer to COMPUTERIZED ENGINE CONTROLS

Vacuum leak ^ Inspect vacuum hoses for proper routing and damaged lines
^ Check intake manifold and throttle body base