car idle roughly, causes

while idling car runs roughly, when coming to a stop car will sometimes stall.

otherwise car will run perfect.

typical causes

1. sparkplugs/wires/coils

2. dirty throttle body

3. idle air control valve

4. bad timing

sparkplugs/wires/coils

damaged, old, sparkplug wires can easily cause misfiring that in turn will give you a rough idle. old, worn ,wrong sparkplugs will also lead to misfiring. your coils if worn out or damaged will give you the same symptoms, if you never changed your sparkplugs and

wires, this will be the perfect time to change them,

dirty throttle body

a dirty throttle body is one of the possibilities of rough idle, inspect your throttle body and if you see any black sooth or dirt, buy a throttle body cleaner and carefully spray it in there and wipe it off, you should feel immediate change in idle.

idle air control valve

iac valve is responsible for keeping your idle steady while idling, coming to a stop, braking ect.

after year of service the iac can become dirty and not be able to keep op with the car demands, that in turns will cause you rough and erratic idle. you can remove it and clean it if possible, or change it.

bad timing

slightly bad timing will cause your car to idle roughly but often it will drive good if the timing is not to far of. remove your timing belt cover, and inspect your timing marks, inspect it closely because it could be just a tooth off