PREVOST LE MIRAGE XLII BUS SHELLS, Руководство по обслуживанию

Страница: 80 / 1260

Section 03: FUEL SYSTEM
PA1564
14
10. FUEL COOLER
The fuel cooler serves to cool the surplus diesel
fuel after it has exited the cylinder head, on its
way back to the fuel tank. It is accessible
through the engine radiator door, and is located
in front of the charge air cooler (CAC) and the
coolant radiator (Fig. 13 &14).
FIGURE 13: FUELRETURN LINE
03078
FIGURE 14: FUEL COOLER LOCATION
03079
11. FUEL PEDAL
The EFPA (Electronic Foot Pedal Assembly)
connects the accelerator pedal to a
potentiometer (a device that sends an electrical
signal to the ECM, which varies in voltage,
depending on how far down the pedal is
depressed). The EFPA is installed in the space
normally occupied by a mechanical foot pedal. It
has maximum and minimum stops that are built
into the unit during manufacturing.
11.1 FUEL PEDAL ADJUSTMENT
The EFPA contains a throttle position sensor
that varies the electrical signal sent to the ECM.
The sensor must be adjusted whenever an
EFPA is serviced. In addition, the sensor should
be adjusted any time codes 21 and 22 are
flashed.
With the ignition "ON" and the proper diagnostic
tool (DDR) (for information regarding the DDR,
see
"01 ENGINE" in this manual), check the
throttle counts at idle and full throttle positions.
Proper pedal output should be 20/30 counts at
idle and 200/235 at full throttle. If adjustment is
necessary, remove the potentiometer retaining
screws and rotate the potentiometer clockwise
to increase counts or counterclockwise to
decrease. When correct output is confirmed,
tighten retaining screws.
11.2 POTENTIOMETER REPLACEMENT
1. Disconnect cable harness connector.
2. Loosen the two screws and remove
potentiometer. Retain for re-assembly.
3. Discard potentiometer (Fig. 15).
CAUTION
Note the routing and clamping locations of the
cable before disassembly. Proper cable
routing and fastening is critical to the
operation of this system. Marking the foot
pedal assembly to record cable routing is
recommended.
4. Position new potentiometer. Press
potentiometer onto the potentiometer shaft,
matching cutouts in shaft to drive tangs of
potentiometer. Apply hand pressure until
potentiometer has bottomed out in housing.
Reinstall screws (Fig. 15) and tighten just
enough to secure potentiometer lightly. Tighten
screws to 10 - 20 Lbf-in (1.13 - 2.26 Nm).
5. Reconnect electronic foot pedal assembly's
cable harness to the ECM connector. If
potentiometer calibration is necessary (see
"FUEL PEDAL ADJUSTMENT" in this
section).