Some possible reasons that a car stalls include a defective airflow sensor, an engine vacuum leak or a faulty coolant sensor. Other potential reasons a car stalls include a defective speed control system or low engine compression.
A car stalls when the airflow sensor is contaminated by dirt or fuel varnish. This messes up the balance of air and fuel in the car, which causes stalling. Use aerosol cleaner cans to clean the airflow sensor wire and fix the stalling.
Another reason a car stalls is because of low engine compression, which often occurs for cars that have many miles on them. Fixing low engine compression involves replacing the entire engine. Cars with worn spark plugs are prone to ignition misfire which causes stalling; replace the spark plugs and wires to correct any hesitation.
Using bad gasoline may be the root of a stalling issue. Gasoline that contains more than 10 percent alcohol causes engine stalling. Contaminated gasoline does not burn well and also causes hesitation. Drain the bad fuel and refill your tank with fresh gas to fix the issue.
If the engine stalls suddenly while you are driving, the cause may be a broken crankshift position sensor, a broken ignition coil or a faulty ignition switch. Low system voltage also causes stalling as well as faulty air temperature sensors.