4TNV94 4TNV98 Used Fuel Injection Pump 729929 - 51330 DX55 - 9 Excavator

Specification

Description

What is a Fuel Pump Relay?

The fuel pump relay sends a current to the electric fuel pump.

A fuel pump relay is an electrical device much like an automotive fuse. It directs current to the electric fuel pump and ensures that the part receives enough power to operate properly, but not too much as to damage it. Fuel pumps require a lot of power to operate and this could cause overheating of the wiring system and the pump if were not for the relay.

In most automobiles, the fuel pump relay is underneath the vehicle's hood and attached to the firewall. It is a small black plastic box with a wiring harness plugged into the bottom of it. The relay operates as a monitor for the power going to the fuel pump, activates it when the ignition is turned on, and turns the pump off when the vehicle is turned off. The fuel pump can be heard humming when the ignition switch is first turned to the on position. This provides fuel for the vehicle to start up, and once the vehicle is running, the vehicle's computer sends a signal, and the fuel pump relay turns off. The vehicle's fuel pump will now be powered through another source, typically in the oil pressure sending unit.

Injection Process

Smaller engines, such as those in cars and light trucks, use a distributor pump to control the fuel injection process. The injector pumps gas or diesel into fuel lines, which is how the volume of fuel is controlled. The timing of the injection process is controlled by the crankshaft. Essentially, the faster a vehicle moves, the more fuel is injected into the internal combustion engine. This can be accented with the addition of a turbocharger or supercharger, which gives the engine more power.