Engine Lugging On Track Feller Bunchers [TIBU4038]

ENGINE ARRANGEMENT

Engine Lugging On Track Feller Bunchers

CONFIDENTIAL TIBU4038-01

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TECHNICAL INFORMATION BULLETIN	February 25, 2004
Track Feller Bunchers	TK711 (1011 - Up) TK721 (1021 - Up) TK722 (1031 - Up) TK732 (1041 - Up) 1090 (BZJ1 - Up) 1190 (BZK1 - Up) 1190T (BZL1 ? Up) 1290T (BZM1 ? Up)
	Component Code 1000

SUBJECT: Engine Lugging on Track Feller Bunchers

PROBLEM: Engine lugging on certain TK711, TK721, TK722, and TK732 needs to be corrected. Certain Track Feller Bunchers experience engine lugging consistently below 1750 rpm. As a result, the machine operator experiences poor (slow) multi-functioning of hydraulic controls, engine lugging, poor fuel economy and loss of productivity.

SOLUTION:

Perform the following troubleshooting procedures:

Verify that you do not have faulty or bad engine fuel injectors. Perform the "Cylinder Cutout Test". Verify that cutting out a specific cylinder causes the engine speed to drop approximately 130 RPM. Replace bad injectors.

Increase the pump output flow. Perform the "Pump Flow ? Test and Adjust".

Perform the "Hydraulic Main Torque Limit Adjustment Procedure."

Cylinder Cutout Test

NOTE: Typically, problems with the injector solenoid occur when the engine is warmed up and/or the engine is under heavy vibration (heavy load). Perform this test with a hydraulic flow meter. The flow meter will be used to load the engine.

Reference: Systems Operation Testing and Adjusting Manual, RENR6284, "Pump Flow - Test", for the required tools to install a hydraulic flow meter on the machine.

NOTE: The injectors can be individually cut out to aid in troubleshooting misfire problems. Use the Cylinder Cutout Test on Cat ET to disable individual injectors.

Reference: Troubleshooting Manual for C-9 Engine SENR9806, "Electronic Service Tools" for the required service tools for the use of Cat ET.

Illustration 1

Plumb flow meter inlet to main pump right-hand outlet (implements).

Illustration 2

Remove filter cover. Remove filter bypass valve and spring. Reinstall filter cover.
Remove the plug from the filter cover. Install a 6V9875 Connector onto the filter cover. Plumb outlet of flow meter to the 6V9875 Connector.

Illustration 3

Remove and plug LS line from valve to pump at pump X4 port.
Connect pump A1 port to X4 port to supply pump outlet pressure to LS signal port and bring pump to maximum displacement during test.
Start the engine.
Allow the engine to warm up to normal operating temperature 77? C (171?F).
After the engine is warmed to operating temperature, access the "Cylinder Cutout Test" by accessing the following display screens in order:

? "Diagnostics"

● "Diagnostic Tests"

● "Cylinder Cutout Test"

Illustration 4

Set the engine speed to high idle (2250 RPM).
Increase the load on the engine by turning the load valve (clockwise) on the flow meter until you lug the engine to 2100 RPM or until you hear a misfire in the engine.
Use the cylinder cutout test in order to cut out individual cylinders manually. This is done by highlighting each cylinder and selecting "Change". The Mode the cylinder will change from "Powered" to "Cutout".
Monitor the Engine Speed.
Perform the test three times.
Verify that cutting out a specific cylinder causes the engine speed to drop approximately 130 RPM.
Compare the results that are found when other cylinders are cut out.
A mechanical problem with the injector may exist if a specific cylinder is cut out and only a slight drop to the engine speed occurs. Replace the injector.

Reference: Disassembly and Assembly Manual for C-9 Engines, SENR9502, "Unit Injector ? Remove" and Unit Injector - Install" for the procedure to replace the injectors.

Then Perform the "Pump Flow ? Test and Adjust ".

Pump Flow ? Test and Adjust

Reference: Systems Operation Testing and Adjusting Manual, RENR6284, "Pump Flow - Test", in order to measure the pump flow. Increase the pump flow to the flow rate specified in the following table.

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Pump Flow Test
		Measuring Points
		700psi (4830 kPa)
Flow measured liter/min (US gpm)	Implement Pump
	Travel Pump
Minimum Oil Temperature 40?C (104?F)
Engine speed (rpm)		2250 rpm
Specification for flow rate liter/min (US gpm)	New	367 ? 3.7 L/min (97 ? 1 US gpm)

NOTE: Perform the test for the implement pump and the test for the travel pump one at a time.

Reference: Systems Operation Testing and Adjusting Manual, RENR6284, "Pump Control (Output Flow)" in order to adjust the maximum output flow of the implement and travel pump.

NOTE: Then Perform the "Main Pump Torque Limit Adjustment Procedure ".

Main Pump Torque Limit Adjustment Procedure

This adjustment does not increase or decrease engine horsepower. Its function is to maximize pump flow and pressure to the horsepower available. This prevents engine lugging and premature engine failure, which is the object of the system. Adjust to specifications only.

NOTE: If the horsepower adjustment is turned out beyond specifications, or if time and wear have altered the adjustment, the pumps will reduce flow sooner than required; the engine will not be called upon to develop its full horsepower; and the machine will be described as LACKING POWER.

Install the new IQAN software for your machine.

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IQAN Software
Models	Version 2.04
TK711, 721, 722, 732	250-3043
1090, 1190, 1190T, 1290T	251-4301

Warm machine up to 50C +/- 15C.

Locate machine on flat surface (dirt or concrete) with no obstructions within full working envelope of machine.

Turn Saw off.

Set machine to Mode 1.

Turn dial speed to high idle (2250 RPM)

Raise boom up to full cylinder extension.

Graph the following channels in IQAN:

Engine Speed (XT2-A0 T0-J1939)

Engine Torque (XT2-A0 T0-J1939)

Eng Boost Press (XT2-A0 T0-J1939)

Eng Fuel Delivery Press (XT2-A0 T0-J1939)

Left Track fwd/rev sol (XT2-A0 T0-Physical I/O)

Implement Pump Press (XT2-A0 T0-Physical I/O)

Travel Pump Press (XT2-A0 T0-Physical I/O)

Boom up/dn Sol (XP2-A0 P0)

Swing cw/ccw Sol (XP2-A0 P0)

Power management (MDM-Calc)

Illustration 5

Simultaneously command the following functions:

? Boom up (stalled)

● Full swing left (this function is NOT stalled)

● Full left travel in the rabbit mode.

NOTE: This will pull the engine down. Continue to hold the 3 functions for 3 seconds.

Review the IQAN graph to determine the minimum speed the engine was pulled to. Also verify the travel pressure was above 100 bar on average during the test. If it is not, duplicate the test in softer soil conditions to apply more load on the tracks (instead of on concrete for example).

Stop and repeat test 3 times. Average the lowest RPM values. The target speed is 1750-1800 rpm.

Illustration 6

Turn both torque limiter screws clockwise an equal amount to decrease the minimum speed. Turn both torque limiter screws counterclockwise an equal amount to increase the minimum speed. Caution: this adjustment is very sensitive. 1/4 turn will change the speed approx 90 rpm.

NOTE: The mechanism can be jammed if the screw is turned in too far.