Actron Professional Fuel Pressure Tester Kit CP7838 - Manual (Page 2)

Fuel Tank: A large container that holds vehicle’s
supply of fuel.
Fuel Pump Filter: A filter that is usually located
in fuel tank. Its function is to prevent foreign
particles from reaching the fuel pump. A clogged or
restricted fuel pump filter can cause low fuel
pressure readings. When replacing a fuel pump it
English
Fuel Injectors Fuel Pressure Regulator
Pressure Line
Return Line
Ford CFI Throttle Body GM Multi-Port Fuel Injection
Fuel Injectors
Fuel Rail
Test Port Fuel Pressure
Regulator
Pressure
Line
Return
Line
Fuel Injectors
Fuel Injectors
Fuel
Rail
Test
Port
Fuel Pressure Regulator
Fuel Rail
Vacuum Port
Fuel Injectors
Return Line
Fuel Filter
Fuel Tank
Fuel Pump Fuel Pump Filter
Pressure Line
Fuel Injection System Theory
There are two basic types of fuel injection systems currently being used. The first type is called
“port” or “multi-port” fuel injection. In this system, fuel injectors spray fuel directly into intake manifold
behind intake valve. These systems typically have one fuel injector per cylinder. The second type is
commonly called Throttle Body Injection (TBI) for GM and Chrysler vehicles or Central Fuel Injection
(CFI) for Ford vehicles. These systems use one or two fuel injectors mounted on top of intake manifold.
They spray fuel into throttle body similarly to a conventional carburetor.
Fuel System Components
Before doing any fuel pressure testing, it is a good idea to understand how fuel system
components work and how they relate to one another. The fuel pump pumps fuel from the fuel tank to
the fuel pressure regulator and fuel injectors. Fuel pressure regulator divides fuel between the pressure
line and return line. The fuel in the pressure line goes to fuel injectors, while fuel is returned to fuel tank
through the return line.
is a good idea to replace the fuel pump filter.
Fuel Pump: An electric motor that pumps fuel
into the fuel system at a constant pressure. It is
mounted in the fuel tank or on the frame. Some
vehicles have more than one fuel pump.
Return Line: Path way for excess fuel to return
to the fuel tank.