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 supply. ^ Check fuel supply.

Faulty fuel pressure regulator. ^ Check fuel pressure.

Contaminated fuel. ^ Check for water or excessive alcohol in fuel. Alcohol/Contaminants-In-Fuel Testing Procedure
^ Drain fuel tank and add clean fuel.

Dirty fuel filter. ^ Replace fuel filter.

Lean operating condition. ^ Check computer controls.
[1][2]Diagnostic Circuit Check - With TBI

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