Ignition & Fuel System - Fuel, Air & Emission Symptoms
Common symptoms and diagnostic guides.
Engine only feels rough at low revs
A rough engine feeling at low revs is usually caused by issues in the ignition, fuel delivery, or air intake systems, leading to unstable combustion and vibrations at idle or low speed.
Car runs rough during nighttime
A car that runs rough specifically during nighttime often points to engine performance issues such as ignition, fuel delivery, or sensor problems that disrupt smooth combustion.