Engine Maintenance
107
If the pump does not operate, check for:
•
A good ground on the black wire pin of the
pump harness
•
More than 9 Vdc on the red wire pin of the
pump harness
•
Clean and tighten the electrical connections
•
The pump voltage and polarity must be the
same as the unit system.
If the pump operates but does not deliver
fuel, check for:
•
Air leaks in the fuel lines or connections
•
Kinks or other restrictions in the fuel lines
•
A leaking or distorted fuel bowl gasket
•
A clogged or dirty filter.
Electric Fuel Heater (Optional)
See “Electric Fuel Heater (Optional)” on page 93
for information about the electric fuel heater.
Engine Speed Adjustments
When the diesel engine fails to maintain the
correct engine speed, check the following before
adjusting the speed:
1. Check the fuel filter in the electric fuel pump.
Check the speed.
2. Bleed the air out of the fuel system. Check the
speed.
3. Bleed the air out of the nozzles. Check the
speed.
Make the engine speed adjustments with the
engine fully warmed up.
High Speed
NOTE: To achieve proper refrigeration system
capacity in High Speed engine operation, it is
important to ensure the engine high speed
throttle is set properly.
1. Shut the unit off.
2. Remove the ball socket from the throttle
bracket ball (see Figure 170).
3. Energize the throttle solenoid by using the
Output Test Mode to energize the high speed
solenoid while the engine is not running.
4. Adjust the ball socket on the end of the
linkage rod as necessary to make it align with
the throttle bracket ball with the throttle
bracket held tight against the high speed stop
screw.
5. If alignment is not possible or there is a slight
gap between the high speed stop screw and
throttle bracket, de-energize the solenoid and
shorten the linkage by threading the ball
socket in up to one turn. Reassemble and
energize the solenoid. Verify that the throttle
bracket is tight against the high speed stop
screw.
Low Speed
1. Loosen the jam nut on the low speed
adjustment screw (see Figure 170).
2. Use the Service Test Mode to run the unit in
low speed. Adjust the screw to obtain the
correct speed. It should be 1450 ± 25 rpm with
a full load.
3. Tighten the jam nut and recheck the speed.
1.
High Speed Solenoid
3.
Ball Joint
4.
Linkage Rod
5.
Low Speed Adjustment Screw
6.
High Speed Stop Screw
Figure 170: Engine Speed Adjustments
ARA2095
1
2
3
4
5
6
