Fundamentally, fuel pumps stick due to contamination, wear, and mechanical problems that happen to the internal components of the pump. Most often, it is caused by some form of debris, dirt, or fuel residues that block or restrict the movement of internal parts within the pump. With time, the contaminants collect in the fuel tank and then enter the pump to cause sticking. It has also been proven that the cars which run on lower quality fuel, or fuel containing a high content of ethanol, are likely to give rise to pump issues by up to 25%, since these fuels do leave more residues.
Aging and mechanical wear are some other causes of sticking. Wear on moving parts within the pump, such as armature and brushes, occurs over years of use and usually becomes less effective. As they get older, these parts could cause friction or misalign, making the pump sticky or slow. On this, experts say the replacement of a fuel pump is usually necessary every 100,000 miles, especially because sticking normally occurs when the pump approaches the end of its expected service life.
Another active ingredient that might cause the sticking of a fuel pump is heat. Fuel pumps inside the fuel tank rely on fuel to keep them cooled, and driving on low fuel consistently overheats the pump. This might cause internal parts to warp or otherwise get damaged and probably stick. Statistics show running a car regularly with a quarter-tank or less can cut the life span of a fuel pump by 20%, and it is often because overheating causes sticking problems.
In addition, there is corrosion, mostly when water enters the fuel tank. Water causes rust or corrosion, which can affect the moving parts of the pump, causing sticking. This mainly applies to those vehicles that are not put into use over a long period of time because of condensation, which usually forms in the tank after some time.
The causes of Fuel Pump sticking include contamination, wear and tear, low levels of fuel inside the tank, and corrosion. With routine maintenance, proper quality fuel, and maintenance of fuel level at least a quarter of the capacity, sticking of the fuel pump can be avoided, hence there assured performance is for a longer time reliably.