Will bad spark plugs or spark plug wires cause a car engine to rev up on it own?
ok i read through all the answers that people have given u and one answer seemed to be the closest. sounds to me like u have a idle air control problem no the tune up will not cause this nor will off timing there is no way for your timing to be off the motor has a timing belt there is no choke pull off because its not carburated and EGR will not cause an idling problem but will cause a misfire the IAC IDLE AIR CONTROL motor is an electric motor that act like a pintle on a screw the motor turns the screw according to the ecm to either let unmetered air in to increase idle or it remains closed to lower desired idle. its all computer controled have a local mechanic plug into the car and pull a data stream see if the IAC is stepping like its supposed to in the morning ist common for all fuel injected cars to have an initial idle of 1250 1500 rpm for 2 to 5min its called cold idle control its a program in the ecm that the ecm runs when certain conditions from certain sensor are found like c
