Generac Power Systems GP Series Diagnostic Repair Manual page 12

Section 2 Electronic Engine Control
Fuel Pump
See Figure 2-13. The fuel pump is located in fuel tank.
The fuel pump (FP) (Item A) receives 12 VDC supply
voltage from MPR to activate and deliver fuel to the fuel
injectors.
Figure 2-13. Fuel Pump
Throttle Body and Electronic Throttle Controller
See Figure 2-14. The electronic throttle controller (ETC)
(Item B) is integrated with the throttle body. The ETC
receives signal from the ECM to open and adjust the
valve in the throttle body and allow air to flow into the
combustion chamber.
Figure 2-14. Throttle Body with Electronic Throttle
Controller
Fuel Injectors
See Figure 2-15. The fuel injectors (INJ1 and INJ2)
receive fuel from the fuel tank via a fuel line connected to
the fuel pump. A control signal from the ECM activates
the injectors to deliver a cone shaped spray of fuel into
the cylinder head combustion chamber.
Figure 2-15. Fuel Injector
6
Ignition Coils
See Figure
signal from the ECM to generate and deliver a high
voltage signal to the spark plugs.
A
Throttle Position, Temperature and Manifold Air
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Pressure Sensor
See Figure
manifold air pressure sensor (TTMAP) (Item C) monitors
throttle temperature and manifold air pressure going into
the engine. These parameters are sent to the ECM to
assist in maintaining optimal spark and fuel delivery while
the unit is running.
C
B
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Figure 2-17. Throttle, Temperature, Manifold Air
Crankshaft Position Sensor
See Figure
(CKP) senses the timing teeth on the flywheel as it
rotates. The flywheel has a 24 minus one tooth design
where one position has no tooth present. The CKP
senses this gap during rotation and sends that signal to
the ECM to determine the position of the crankshaft and
camshaft.
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2-16. The ignition coils (IC1 and IC2) receive
Figure 2-16. Ignition Coil
2-17. The throttle position, temperature and
Pressure Sensor
2-18. Input. The crankshaft position sensor
Diagnostic Repair Manual
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