If a vehicle's engine only starts when it's cold but not when it's warmed up, it's reasonable to suspect that one of the electronic sensors in the fuel injection system has gone bad. A bad sensor can throw off the computer's ability to regulate the amount of fuel the engine gets, leading to a failure to start when the engine is warm. One possible cause is a sensor that is not sensing the outside temperature correctly, resulting in the engine not getting the rich air/fuel mixture it needs to stay running when it's cold.
To diagnose the problem, take the vehicle to a reputable repair garage. The mechanic will likely need to hook up an engine analyzer to determine if any of the sensors are faulty.
The cost of an engine analysis using an engine analyzer can vary depending on several factors, including the location of the repair shop, the make and model of the vehicle, and the extent of the analysis required. Generally, the cost for an engine analysis can range from $40 to $70, but it could be higher depending on the factors mentioned above. It's best to check with your local repair shop to get an accurate estimate., in addition to the charges for replacing any faulty sensors. In most cases, only one sensor is the culprit, in addition to the charges for replacing any faulty sensors. In most cases, only one sensor is the culprit.
If the starting problem also happens when the engine is warmed up, locate the fuel pump (refer to the vehicle's manual if you need assistance) and turn the ignition key to the point just before the engine starts to turn over. If the fuel pump is located inside the gas tank, remove the gas cap and listen for a "whirring" sound coming from the tank. If the fuel pump is located under the hood, listen for the same sound coming from the pump. If you hear the sound, it suggests that the electronic fuel pump is working.
However, if you don't hear the sound, it could mean that there is a problem with the fuel injection system, such as a bad electric fuel pump. All vehicles with fuel injection have an electric fuel pump that makes a "whirring" type sound when it's working properly. A bad fuel pump will not provide the engine with the fuel it needs to stay running after it starts.
Replacing the fuel pump can be a simple or complex job depending on where it's located. If you feel comfortable doing it yourself, refer to the vehicle's manual for detailed instructions. If not, shop around for the best price and take it to a mechanic who has expertise in the particular make and model of the vehicle. If the mechanic suggests that you need a new fuel injection system, it's highly recommended to get a second opinion, as the problem could be with one of its sensors rather than the system itself.
