Operation CHARM: Car repair manuals for everyone.

Surges at Steady Speed

SYMPTOM DESCRIPTION
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 flow ^ Check fuel pump volume.


Faulty fuel pressure regulator ^ Check fuel pressure.


Contaminated fuel ^ Check for water or excessive alcohol in fuel.


Restricted fuel filter ^ Replace fuel filter.


Lean air/fuel mixture ^ Check computer controls. SEE Computers and Control Systems. Computers and Control Systems


Plugged fuel injector ^ Perform injector balance test.


Vacuum leak ^ Inspect vacuum hoses for proper routing and damaged lines.

^ Check intake manifold/throttle body area.