Q: I started my car this morning and went to put it in drive. As soon as I took my foot off the brake to give gas it shut off completely.

This may be related to a couple of possible things. There is a component called an idle air control valve that monitors the air intake as it is mixed with fuel prior to being injected into the engine at low speeds and at idle. This valve is controlled by the vehicle’s computer which will adjust idle speed based upon other measurements such as engine temperature, intake air temperature and electrical system load or voltage. When you accelerate, the engine RPM increases, and as you let off the gas, the RPM slowly returns to the normal idling speed. This is all controlled by the idle air control valve.

When the engine RPM drops below the normal range of 750-800 RPM (for most cars), this may indicate a dirty or faulty idle air control valve. As in your case, your vehicle may stall when you attempt to increase the RPM’s beyond an idle speed.

This may also be related to a throttle position sensor. The throttle position sensor (TPS) is a sensor used to monitor the throttle position of the throttle plate inside the throttle body in relation to your foot position on the gas pedal. Based upon the inputs from the sensor reading your foot’s position on the pedal, the ECU then makes the direction to supply more or less fuel to the motor. When this sensor is not working properly, this can cause intermittent responses when pressing the gas pedal as you have noticed when taking your foot off of the brake.

To avoid any unnecessary repairs, I would suggest having a professional from YourMechanic come to your home to diagnose your stalling condition firsthand and service your throttle control system and idle air control valve as necessary.