One of the frustrating issues that car owners may encounter is when their car starts but fails to stay running. This problem can be particularly troublesome when it occurs only when the engine is cold.

In such cases, the likely culprit could be a bad electric sensor in the Fuel injection system. On the other hand, if the starting problem persists regardless of the engine temperature, it could indicate an issue with the fuel injection system itself or a faulty electric Fuel Pump.

When the starting problem occurs only when the engine is cold, it is reasonable to suspect that one of the electronic sensors in the fuel injection system has gone wrong. These sensors play a crucial role in regulating the amount of fuel the engine receives. If a sensor fails to detect the cold outside temperature accurately, the engine may not receive the rich air/fuel mixture necessary to stay running in cold conditions.

To diagnose and resolve this issue, it is advisable to take the car to a reputable repair garage. The mechanic will likely connect the engine to an engine analyzer to identify any faulty sensors. Typically, the analysis fee ranges from $40 to $70, and the mechanic may charge additional fees for replacing the faulty sensor(s). Fortunately, in most cases, only one sensor is usually responsible for the problem.

However, a different approach is required if the starting problem persists regardless of the engine temperature. In such cases, it is recommended to check the fuel pump. By referring to the car's manual, locate the fuel pump and turn the ignition key to the point just before the engine starts turning over. If the fuel pump is inside the gas tank, remove the gas cap and listen for a "whirring" sound coming from the tank. If the fuel pump is under the hood, listen for the same sound directly from the pump. This sound indicates that the Electric Fuel Pump is functioning correctly.

If the "whirring" sound is absent, it suggests a potential problem with the fuel injection system. Fuel injection systems can be complex and challenging to diagnose. If the car is not under warranty, it is advisable to take it to a mechanic specializing in the particular make and model. Seeking a second opinion if the first mechanic recommends replacing the entire fuel injection system is highly recommended. In many cases, the issue lies with one of the system's sensors rather than the system itself, and an experienced mechanic can accurately identify the faulty component.

On the other hand, if no "whirring" sound is heard from the fuel pump, it is likely that the electric fuel pump is faulty. Electric fuel pumps are essential components of fuel-injected cars. They provide the engine with the necessary fuel after it starts. Since you did not hear the characteristic sound of a working fuel pump, it is reasonable to suspect that the electric fuel pump needs to be replaced.

Replacing the electric fuel pump can be a straightforward or complex task, depending on its location. If you feel confident in your abilities, the car's manual will provide detailed instructions for removing and replacing the fuel pump. Alternatively, you can shop around for the best price and have a professional mechanic handle the replacement for you.

In conclusion, a car that starts but won't stay running can be attributed to various causes depending on whether the issue occurs only when the engine is cold or persists regardless of the temperature. A bad electric sensor in the fuel injection system is a likely culprit when the starting problem is temperature-dependent. However, if the problem persists, it could indicate issues with the fuel injection system itself or a faulty electric fuel pump. Consulting a qualified mechanic and getting a proper diagnosis is essential for resolving the issue effectively.