How to judge whether the idle vibration of cold car is spark plug or ignition coil, nozzle or throttle?

It's hard to judge. It is impossible for fuel injectors. When the car is cold, it is difficult to judge the spark plug and ignition coil by looking at the throttle opening through the data flow. It is suggested that the spark plug can be replaced first according to the mileage of the spark plug. If the car is just cold, the carbon deposit on the engine should be removed. Please adopt it if it helps you.