when I start the car in the morning or when cold the car would idle high and struggle to keep the idle up. After a min or two it would stall out and restart fine. once it warm up the car's rpms would jump up and down between 500 and 1000 rpm it would never stop. lately the car would drive about ten min and then hesitate really bad and stall but will start right back in and drive fine. I have changed the mass airflow sensor, throttle sensor, and cleaned throttle body and changed spark plugs. I only had the car for a month and can't drive it more than a week. The previous owner that had the car and never drove it, only twice in the last year. NEED HELP.
My car has 59000 miles.
My car has an automatic transmission.
It sounds like you may have a dirty or failing idle air control valve causing your engine idle to fluctuate. The idle air control valve is a small valve on the engine’s intake system that reads the air intake as it comes into the motor. This is controlled by the car’s ECM which uses this information to make adjustments to the air/fuel ratio depending on various inputs such as outside air temperature, intake air temperature, load and various other things. As you accelerate, your car’s engine is receiving a much higher dose of fuel than when at idle and conversely, when you let off the gas pedal, there is a sudden change in this fuel supply as a result of your foot letting off the pedal. When this happens, the job of the idle air control valve is to bring this deceleration down to a slow and smooth idle rather than suddenly cutting off the fuel supply causing the motor to die. When the idle air control valve is not working properly, this cause a disruption in this process resulting in the engine not being able to idle properly. I would recommend having a professional come to your location to diagnose and inspect your vehicle.
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