6E1–310
X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
028RX002
GENERAL DESCRIPTION — FUEL
METERING
Acceleration Mode
The ECM provides extra fuel when it detects a rapid
increase in the throttle position and the air flow.
Accelerator Controls
The accelerator control system is a cable–type system
with specific linkage adjustments.
Refer to Cable Adjustment.
Battery Voltage Correction Mode
When battery voltage is low, the ECM will compensate for
the weak spark by increasing the following:
D
The amount of fuel delivered.
D
The idle RPM.
CMP Signal
The ECM uses the camshaft position (CMP) sensor
signal to determine the position of the number 1 piston
during its power stroke, allowing the ECM to calculate
true sequential multiport fuel injection (SFI). Loss of this
signal will set a DTC P0341 or DTC P0342. If the CMP
signal is lost while the engine is running, the fuel injection
system will shift to a calculated sequential fuel injection
based on the last fuel injection pulse, and the engine will
continue to run. The engine can be restarted and will run
in the calculated sequential mode with the fault is present,
with a 1–in–4 chance of being correct.
Clear Flood Mode
Clear a flooded engine by pushing the accelerator pedal
down all the way. The ECM then de–energizes the fuel
injectors. The ECM holds the fuel injectors de–energized
as long as the throttle remains above 80% and the engine
speed is below 800 RPM. If the throttle position becomes
less than 80%, the ECM again begins to pulse the
injectors ON and OFF, allowing fuel into the cylinders.
Deceleration Fuel Cutoff (DFCO) Mode
The ECM reduces the amount of fuel injected when it
detects a decrease in the throttle position and the air flow.
When deceleration is very fast, the ECM may cut off fuel
completely for short periods.
Engine Speed/Vehicle Speed/ Fuel Disable
Mode
The ECM monitors engine speed. It turns off the fuel
injectors when the engine speed increases above 6000
RPM. The fuel injectors are turned back on when engine
speed decreases below 5750 RPM.
Fuel Cutoff Mode
No fuel is delivered by the fuel injectors when the ignition
is OFF. This prevents engine run–on. In addition, the
ECM suspends fuel delivery if no reference pulses are
detected (engine not running) to prevent engine flooding.
Fuel Injector
The sequential multiport fuel injection (SFI) fuel injector is
a solenoid–operated device controlled by the ECM. The
ECM energizes the solenoid, which opens a valve to allow
fuel delivery.
The fuel is injected under pressure in a conical spray
pattern at the opening of the intake valve. Excess fuel not
used by the injectors passes through the fuel pressure
regulator before being returned to the fuel tank.
A fuel injector which is stuck partly open will cause a loss
of fuel pressure after engine shut down, causing long
crank times.
0003
Fuel Metering System Components
The fuel metering system is made up of the following
parts:
D
The fuel injectors.
D
The throttle body.
D
The fuel rail.
D
The fuel pressure regulator.
D
The ECM.
D
The crankshaft position (CKP) sensor.