There are many reasons why a car starts but does not stay running, but one of the most common causes of this problem is a bad fuel pump. When a fuel pump is going out, it is common for a car to stop running abruptly when the fuel supply becomes restricted.
It is also possible that a fuel line is blocked, causing the restriction of fuel. To test whether or not fuel delivery is the cause, the car owner should push down on the gas pedal when the car begins to die. If this does not stop the car from dying, this indicates there is a problem with fuel delivery.
It is also possible that there is a problem with power getting to the engine. One reason for this is a bad alternator. The alternator is responsible for keeping the battery of a car charged. When the alternator goes out, the battery dies. If the car requires a jump after it stops running, the alternator is most likely the problem. When the battery is the problem, there is a clicking sound when the car is turned over.
Unfortunately, there are a number of other possible causes of a car starting but not continuing to run. The ignition wires could be frayed, the timing may need to be adjusted, or the fuel filter may also need to be cleaned.