Generac Power Systems GP Series Diagnostic Repair Manual page 19

Fuel System
See Figure 2-37. EFI fuel systems consist of a fuel tank mounted pump (with integrated regulator), and an injector.
Fuel is drawn from the tank by the pump, which provides working fuel pressure to the injector. Fuel pressure limit is
controlled by the fuel pressure regulator located in the fuel pump, discharging unused fuel back into the tank. The
injector has a 2-pin electrical plug to carry switching current to the injector. When the injector is energized it allows the
fuel to spray out in a cone like pattern.
A. Fuel Tank
B. Fuel Pump
Operational Analysis
The "Operational Analysis" is intended to familiarize the service technician with the operation of the DC and AC control
system. A thorough understanding of how the system works is essential to sound and logical troubleshooting.
The diagrams in this section describe the following scenarios:
•
Key OFF
• Key ON
• Key ON Starting
• Key ON Running
Legend – Operational Analysis
AVR Automatic Voltage Regulator
CO_MOD Carbon Monoxide Module
CT Current Transformer
DB_ Diode Bridge #
ECM Engine Control Module
EHT Engine Head Temperature Sensor
ETC Electronic Throttle Controller
FBR Field Boost / Fuel Pump Relay
FP Fuel Pump
Diagnostic Repair Manual
Figure 2-37. Return-less Fuel System
C. Fuel Gauge
D. Fuel Gauge Float
IAT Intake Air Temperature Sensor
IC_ Ignition Coil Cylinder #
INJ_ Fuel Injector Cylinder #
KSS Key Start Switch
MAP Manifold Air Pressure Sensor
MIL Malfunction Indicator Lamp
MPR Main Power Relay
OPS Oil Pressure Switch
OS Exhaust Gas Oxygen Sensor
Section 2 Electronic Engine Control
E. Pressure Line
F. Fuel Injector
TTMAP TPS, IAT, and MAP 3-in-1 Sensor
015018
G. Fuel Filter
H. Air Filter Hose
R1 Resistor 1
SC Starter Contactor
SM Starter Motor
STR Starter Relay
TPS Throttle Position Sensor
VR Voltage Regulator
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