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 pump output volume Check fuel pump output volume. Fuel System Diagnosis

Faulty fuel pressure regulator Check fuel pressure. Fuel System Diagnosis

Contaminated fuel ^ Check for water or excessive alcohol in fuel. Alcohol In Fuel Test
^ Drain fuel tank and add clean fuel

Dirty fuel filter Replace fuel filter

Lean operating condition Check computer controls.

Plugged fuel injector Perform injector service (cleaning).

Vacuum leak Inspect vacuum hoses for proper routing and damaged lines, check intake manifold/throttle body area