JLG 740AJ, Руководство по обслуживанию и ремонту

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SECTION 3 - CHASSIS & TURNTABLE
3121160 3-141
3.27 DUAL FUEL SYSTEM
IT IS POSSIBLE TO SWITCH FROM ONE FUEL SOURCE TO THE OTHER WITHOUT
ALLOWING THE ENGINE TO STOP. EXTREME CARE MUST BE TAKEN AND THE
FOLLOWING INSTRUCTIONS MUST BE FOLLOWED.
Changing from Gasoline to LP Gas
1. Start the engine from the ground control station.
2. Open the hand valve on the LP gas supply tank by turn-
ing counterclockwise.
BE SURE ALL GASOLINE IS EXHAUSTED BEFORE SWITCHING TO LP GAS.
3. While the engine is operating, place the two position
LPG/Gasoline switch at the platform control station to
the LP position. Allow the engine to operate without
load until the engine regains smoothness.
Changing from LP Gas to Gasoline
1. With engine operating on LP under a no load condition,
throw the LPG/Gasoline switch at the platform control
station to the “Gasoline” position. Allow the engine to
operate with no load until the engine regains smooth-
ness
2. Close the hand valve on the LP gas supply tank by turn-
ing clockwise.
3.28 EFI ENGINE
Performing Diagnostics
1. Verify the complaint and determine if it is a deviation
from normal operation.
2. Once the complaint has been verified, preliminary
checks can be done. Conduct a thorough visual inspec-
tion, be alert for unusual sounds or odors, and gather
diagnostic trouble code information.
3. Perform a system check that will verify the proper opera-
tion of the system in question and check for recent infor-
mation updates.
4. If a diagnostic trouble code (DTC) is stored, contact a JLG
distributor to make an effective repair.
5. If no DTC is stored, select the symptom from the symp-
tom tables and follow the diagnostic path or sugges-
tions to complete the repair.
6. After the repair has been made and validated for proper
operation, the old part should be momentarily re-
installed to verify that it was indeed the source of the
problem.
If no matching symptom is available, analyze the complaint
and develop a plan for diagnostics utilizing the wiring dia-
grams, technical assistance, and repair history.
Intermittent conditions may be resolved by using a check
sheet to pinpoint the circuit or electrical system component.
Some diagnostic charts contain Diagnostic Aids which give
additional information about a system. Be sure to use all of the
information that is available to you.
VISUAL/PHYSICAL ENGINE INSPECTION CHECK
Perform a careful visual and physical engine inspection before
performing any diagnostic procedure. Perform all necessary
repairs before proceeding with additional diagnosis, this can
often lead to repairing a problem without performing unnec-
essary steps. Use the following guidelines when performing a
visual/physical inspection check:
• Inspect engine for modifications or aftermarket equipment
that can contribute to the symptom; verify that all electri-
cal and mechanical loads or accessory equipment is "OFF"
or disconnected before performing diagnosis.
• Inspect engine fluids for correct levels and evidence of
leaks.
• Inspect vacuum hoses for damage, leaks, cracks, kinks, and
improper routing, inspect intake manifold sealing surface
for a possible vacuum leak.
• Inspect PCV valve for proper installation and operation.
• Inspect all wires and harnesses for proper connections and
routing; bent or broken connector pins; burned, chafed, or
pinched wires; and corrosion. Verify that harness grounds
are clean and tight.
• Inspect engine control module (ECM), sensors, and actua-
tors for physical damage.
• Inspect ECM grounds for cleanliness, tightness, and proper
location.
• Inspect fuel system for adequate fuel level, and fuel quality
(concerns such as proper octane, contamination, winter/
summer blend).
• Inspect intake air system and air filter for restrictions.
• Inspect battery condition and starter current draw.
If no evidence of a problem is found after visual/physical
engine check has been performed, proceed to MIL DTC
retrieval procedure.