Fuel System Diagnosis; Gasoline Fuel System Diagnosis; Fuel System Description - Kubota WG1605-E3 Diagnostic Manual

WG1605-G-E3,WG1605-L-E3,WG1605-GL-E3, DM

[2] FUEL SYSTEM DIAGNOSIS

Gasoline Fuel System Diagnosis

Fuel System Description

Engines which use the EControls gasoline fuel
injection system will utilize a gasoline fuel tank which is
either part of the chassis or a standalone vessel for the
storage of the gasoline. On EControls USA emissions
certified engines fuel tanks will not have a vented
gasoline tank as the design of the system does not
require the use of any vapor recovery from the fuel tank.
When the engine is operating the fuel is being drawn
from the tank by the suction created from the fuel pump.
A inline fuel filter will be installed either in-line or in the
tank to filter out the small contaminants which may be in
the fuel prior to reaching the fuel pump.
The EControls ECM controls the fuel pump by
varying the supplied voltage to control the outlet
pressure. The pump subsequently "pulses", sending
pressurized fuel to the Fuel Pressure Manifold.
A fuel temperature and pressure sensor mounted in
the manifold measures the gasoline temperature and
pressure for feedback to the ECM. By controlling the fuel
pump outlet pressure, excess fuel is not being sent to the
injector rail and therefore the rail does not have a return
line back to the tank. Any excess pressure is allowed to
"bleed back" to the tank from the Fuel Pressure Manifold.
This method of fuel delivery prevents large amounts of
hot fuel from being returned to the tank from the injector
rail which would normally cause a vapor build up in the
fuel tank and subsequently requiring the need for a vapor
recovery system on the engine.
The fuel pressure is controlled by the ECM and
therefore to properly measure the pressure, the
EControls GCP Display SW is required. On engines
where a test port in the fuel rail has been installed, a
gauge method can be used to measure pressure.
1-93
ECM SYSTEM
KiSC issued 12, 2016 A