I bet I've seen this more than a dozen times on performance street cars. The typical situation is usually a decent sized 6- or 10-gauge power wire from a relay to the electric fuel pump that should supply plenty of voltage and current to the pump. But a closer inspection of the ground side often reveals a short length of 12-gauge-or-smaller wire attached to the body of the car. The first problem is assuming that the car body offers a good ground path back to the battery, which is rarely the case. How many of those factory ground straps have you removed between the body and the engine? Remember, the battery is grounded to the engine, not the body. This makes the ground path from the body to the engine more difficult. But more importantly, if you are using an 8- or 10-gauge wire to feed power to the pump, you need an equally large wire to complete the ground circuit. Small wires create a voltage drop that can make the pump run hot since it's running at a much lower voltage. This not only reduces volume output but also drastically reduces its life expectancy.