Some car owners immediately suspect a fuel pump failure when their cars stall. However, there are many other engine problems that may resemble a fuel pump failure, such as restricted fuel filters, smashed hoses, ignition problems, etc. If your car stalls, you may also want to check the condition of the fuel pump relay.
The fuel pump relay is a device that is connected to the tach sensor of your car. The ignition switch of your car does not power the fuel pump. Instead, it activates the fuel pump relay, which can handle the higher current. The relay uses the impulse of the sensor to know if the engine is running. It allows the fuel pump to work and stays closed as long as the engine is running. When the engine stops running, the relay receives an impulse and it opens up. The impulses are sent in a time constant of one to two seconds.
If your car is having difficulty starting up, then the problem may have to to with a defective fuel pump relay. A fuel pump relay with defective solder joints will have burn marks. Sometimes, the increased resistance of a defective relay can even cause the plastic casing of the unit to melt. Check the relay of your car if it has these burn marks, and replace it if needed.
Many people find it hard to locate the fuel pump relay in their cars. The relay is usually located under the dashboard near the steering column. Sometimes, it is clipped to the crossmember where the steering column is mounted. Typically, the relay is black or yellow with six connectors at one end. When you’ve taken out the relay, check it for burn marks or a burnt odor. You can also try to put your thumb on the relay to see if the big parts move. If they move, then the solder joints must be defective. Also check for solder joints that are crinkly or dull because these indicate that the relay is not in good condition.
You can always have your fuel pump relay replaced if you do not know how to repair it. It is also advisable to bring your car to the repair shop so that the whole engine can be checked.