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 Test fuel system pressure.

Contaminated fuel Test for water or excessive alcohol in fuel. Alcohol In Fuel Test

Dirty fuel filter Replace fuel filter

Lean operating condition Measure 02 sensor voltage.

Plugged fuel injector Perform injector service (cleaning).

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