Common fuel pump problems include worn-out commutators and brushes, burnt connectors, and permanent pump damage due to insufficient lubrication. Corrosion of the fuel pump, which occurs when water enters the fuel system, is also a common problem.
Contaminant particles and other debris in dirty fuel often bypass the strainer and wear out the brushes and commutator on the motor. This forces the motor to use more amperage to produce the same pressure, which burns connectors in the fuel pump. Insufficient fuel limits lubrication and cooling in the pump and often results in permanent damage. The fuel in stored vehicles attracts moisture that corrodes the metal components of the fuel pump.