Causes of fuel pump failure Fuel pumps typically operate for seven to ten years before failure. Premature failures are most commonly caused by one of the following reasons: Excessive Hot/Cold Environments Contaminated fuel Excessively running a vehicle on a near empty tank which prevents the pump from being fully submerged causing it to overheat Prior to Replacing Pump, check: Fuel Pump Fuse(s) Fuel Pump Relay Voltage at the Pump - test for bad wiring Voltage drop test - corroded connector, bad wiring Fuel System Pressure - test for pump pressure being outside accepted rang .
