Fuel pump problems are usually caused by running a car for extended periods of time on a tank that is almost empty. This causes the fuel pump to run dry, which eventually damages the pump. Another cause would be a clogged filter. Contaminants like water, sludge and bacteria can block a car’s filter and impair the pump. In addition, a fuel pump, like all the other components of a car, can simply fail because of prolonged use.
Though a car can simply sputter and die without any warning signs of fuel pump problems, you should always be very observant of a fuel pump’s performance. An early indication of fuel pump problems is when the pump does not start working after two seconds when you start the the car. This means that the pump may be having difficulty pressurizing the system.
If you suspect that your pump has some problems, check if it’s providing sufficient pressure to the system. If it is supplying low fuel pressure, its diaphragm spring may be weak or ruptured. It can also be caused by the physical deterioration of the engine’s moving parts or leaking check valves. A car with low fuel pressure could stall at high engine speeds. Meanwhile, high fuel pump pressure can be caused by a malfunctioning pressure relief valve. This can be very dangerous since fuel might flood the engine.
A mechanical fuel pump that has some problems would sometimes make a clacking noise. This is usually caused by the deterioration of the rocker arm pin or the rocker arm return spring. You should also check your car for fuel pump leaks. Leaks are caused by a broken pump body or the deterioration of the diaphragm and gaskets. When the diaphragm is broken, fuel leaks through a small vent hole in the pump body.
There are other engine problems that have similar symptoms to fuel pump problems. Check your car for restricted fuel filters, smashed hoses, ignition problems, etc. If you are unsure what causes your car to stall, bring it to the repair shop so professionals can have a look at it.