Fuel & Ignition - Fuel, Air & Emission Symptoms
Common symptoms and diagnostic guides.
Engine cruising feels rough
Engine roughness during cruising can come from combustion, fuel, air intake, ignition, or drivetrain vibration issues that affect performance and comfort.
Engine coughs then tiny hop
Engine coughing and slight hopping at idle often indicates a rough idle caused by fuel, ignition or air intake issues, and may require diagnostic checks to prevent progression.