Step by step illustrated explanation of an automotive fuel injection system.
- Fuel injection is used to supply an internal
combustion engine with the proper amount of fuel at any given engine speed. Once
fuel enters the fuel tank its picked up by the
which is situated inside the gas tank. This fuel pump is controlled
by a relay located in the
PDC power distribution center
which is activated by the
Fuel Pump In-Tank
Step 2 - Once pressurized, the fuel travels along
the bottom of the vehicle through fuel lines toward the fuel filter.
Step 3 - Fuel then travels to the
where its cleaned before continuing to the injection rail.
Step 4 - After being cleansed by the fuel filter,
pressurized fuel enters the fuel rail where its distributed to individual injectors.
Step 5 - A
is used to maintain and adjust pressure while the engine
is in use, this device is only used in fuel return style injection systems. Some
fuel injected vehicles are fitted with a regulator at the fuel pump.
Fuel Pressure Regulator
Step 6 - A
is used to
disperse fuel at precise intervals which is controlled by the computer and adjusts
as engine speeds vary.
Step 7 - The
is responsible for producing and adjusting voltage signals which open
and close the injector, allowing fuel into the
The quantity of fuel that enters the engine is determined by the engine management
system while using feedback data which is gathered by various sensors.
are used to monitor the fuel mixture in the exhaust system. A fuel injector can
designed to enter the intake system or the combustion chamber of the engine. The
open duration of an injector is called, pulse width.
Once an engine run-ability problem has materialized, its usually accompanied by
a check engine or service engine soon light. Perform a
or scan to determine the problem, and the subsequent repair needed
to fix the problem. A fuel system can hold pressure for several hours so caution
should be used when working on these systems.
Article first published 2016-04-28