So a fuel pump wasn’t designed to run constantly, but instead off and on depending on how much the engine needs fuel. Initially, the pump runs for a few seconds to prime the system when you turn the key onto the ignition stage, supplying fuel pressurized to a standard for most cars at or around 40-60 PSI. After the desired pressure is attained the pump turns off and only cycles ON again as required to maintain that pressure. It can be due to a failed fuel pump relay, which sends electric power to the pump, causing it to run always. A bad relay will cause the pump to remain on, which will wear the pump out faster, shortening its life by as much as 30%.
This can cause overheating of the fuel pump which will be exacerbated by low fuel levels. In the case of in-tank systems, the pump is cooled by the petrol itself and running low on fuel reduces the effectiveness of this cooling which can cause the pump to overheat. According to reports, running low on fuel can increase pump temperatures by upwards of 20-30 degrees F, which leads to faster wear on internal components of the pump. This is why it is essential to maintain at least a quarter of a tank of fuel to prevent this issue and to keep the pump running efficiently.
The pump may run continuously due to electrical issues, such as wiring-related issues or an ECU failure. An ECU (engine control unit) controls the pump, using data received from sensors that constantly check for feedback regarding fuel pressure, engine speed, and temperature. But in case the ECU detect that the readings are wrong or the signal to turn the pump off is not arrived, it may run the pump on. Being prepared to recognize electrical issues will avert pumped operation on standby and will assist in keeping the petrol pump utilization effective, therefore, delaying the operational life cycle of a pump.
In cases where the Fuel Pump looks to be running constantly, solving these problems is crucial to prevent significant repairs. This would supply long periods of runtime for the fuel pump that would be avoided with regular inspection of the relay and wiring and also the fuel level to provide normal runtime, and hence years of efficient working and longevity of the pump and all other components related to it.