High Leak-off of the Electronic Unit Injector on C6.6 and C4.4 Engines {1251, 1290} Caterpillar

Asphalt Compactor

CB44B (S/N: TWC1-UP)

CB54B (S/N: 4631-UP; S4P1-UP)

Asphalt Paver

AP-500D (S/N: B3D1-UP)

AP1000E (S/N: DKH1-UP)

AP1055E (S/N: TRS1-UP)

AP500E (S/N: JWK1-UP)

AP500F (S/N: 5031-UP; 4491-UP)

AP555E (S/N: A5D1-UP)

AP555F (S/N: AP51-UP; 5F51-UP)

AP600D (S/N: TFM1-UP; TFZ1-UP)

AP655D (S/N: GNN1-UP; MAN1-UP; MAT1-UP; GNZ1-UP)

BG500E (S/N: B5E1-UP)

BG555E (S/N: B5P1-UP)

BG600D (S/N: B6K1-UP)

BG655D (S/N: BPA1-UP)

BG655D MTS (S/N: B5D1-UP)

CB54 (S/N: JLM1-UP)

Backhoe Loader

420E (S/N: PRA1-UP; PHC1-UP; GEK1-UP; DJL1-UP; DAN1-UP)

430E (S/N: MXB1-UP; SWC1-UP; SCD1-UP; RLN1-UP)

450E (S/N: RBA1-UP; EBL1-UP; LYR1-UP)

Compact Wheel Loader

910H (S/N: SAT1-UP)

914G2 (S/N: KNP1-UP)

Excavator

320D (S/N: JZA1-UP; MZD1-UP)

320D L (S/N: KZF1-UP)

323D L (S/N: NZF1-UP)

M313D (S/N: D3W1-UP)

M315D (S/N: D5W1-UP)

Generator Set

C4.4 GEN SET (S/N: D4B1-UP; D4D1-UP; GLD1-UP; GLE1-UP)

C6.6 DE150E2/DE (S/N: GTM1-UP)

C6.6 GEN SET (S/N: LC61-UP; SDA1-UP; N6D1-UP; MRW1-UP)

Industrial Engine

C4.4 (S/N: 4441-UP)

C6.6 (S/N: 6661-UP)

Integrated Toolcarrier

IT14G2 (S/N: ERP1-UP)

IT38H (S/N: JNJ1-UP)

Knuckleboom Loader

C6.6 (S/N: 5591-UP)

Load Haul Dump

R1300G Series II (S/N: RSL1-UP)

Mobile Hydraulic Power Unit

M316D MHPU (S/N: KMA1-UP)

Motor Grader

120M (S/N: R9A1-UP; PJB1-UP; B9C1-UP; R9C1-UP; NJD1-UP; B9N1-UP; CBS1-UP; B9W1-UP; D9W1-UP; RMY1-UP)

12M (S/N: R9B1-UP; B9F1-UP; B9R1-UP)

Pipelayer

PL61 (S/N: WGS1-UP)

Pneumatic Compactor

CW34 (S/N: C341-UP; J3H1-UP)

Soil Compactor

CP54B (S/N: 5461-UP; P5F1-UP; PFM1-UP)

CP56B (S/N: 4381-UP; M5P1-UP)

CP68B (S/N: 6841-UP; SDT1-UP)

CP74B (S/N: 7441-UP; M7B1-UP)

CP76 (S/N: C7L1-UP; JCP1-UP)

CS54B (S/N: 5441-UP; M5B1-UP; MFC1-UP)

CS56 (S/N: JMM1-UP)

CS56B (S/N: 4371-UP; M4M1-UP)

CS64B (S/N: DH61-UP)

CS68B (S/N: 4391-UP; MBF1-UP)

CS74B (S/N: 4411-UP; E7E1-UP)

CS76 XT (S/N: JCS1-UP; CYX1-UP)

CS78B (S/N: 4431-UP; M8M1-UP)

CS79B (S/N: C791-UP)

Track Loader

953D (S/N: LBP1-UP)

963D (S/N: LCS1-UP)

Track-Type Tractor

D3K (S/N: FFF1-UP)

D3K LGP (S/N: JTD1-UP; LLL1-UP)

D4K LGP (S/N: RRR1-UP)

D4K XL (S/N: MMM1-UP)

D5K (S/N: JLF1-UP)

D5K LGP (S/N: YYY1-UP)

D5K XL (S/N: WWW1-UP)

D5R LGP (S/N: D5L1-UP)

D5R XL (S/N: D5X1-UP)

D6K (S/N: NCF1-UP)

D6K LGP (S/N: DHA1-UP)

D6K XL (S/N: HMG1-UP; FBH1-UP)

D6N LGP (S/N: GHS1-UP; DJY1-UP)

D6N XL (S/N: DJA1-UP; JAH1-UP; LJR1-UP; MLW1-UP)

Vibratory Compactor

CB54 (S/N: K3J1-UP)

CB64 (S/N: CB51-UP; DJM1-UP)

CP44 (S/N: MPC1-UP; M4P1-UP)

CP54 (S/N: C5Y1-UP)

CP56 (S/N: C5P1-UP; FCP1-UP)

CP64 (S/N: P7F1-UP; C6P1-UP)

CP74 (S/N: P8F1-UP)

CS-533F (S/N: C5X1-UP)

CS44 (S/N: M4C1-UP; M4S1-UP)

CS54 (S/N: C5R1-UP; C5W1-UP)

CS56 (S/N: C5S1-UP; FCS1-UP)

CS64 (S/N: C7F1-UP; C6S1-UP; WSW1-UP)

CS74 (S/N: C8F1-UP; C8S1-UP)

Wheel Feller Buncher

2470C (S/N: W471-UP; W2M1-UP)

553C (S/N: W531-UP; PGR1-UP)

Wheel Loader

924H (S/N: HXC1-UP; JTM1-UP; KLN1-UP; RRS1-UP; LKW1-UP)

924HZ (S/N: RCB1-UP; WLB1-UP; PED1-UP; JRL1-UP; JZZ1-UP)

928H (S/N: RSB1-UP)

928HZ (S/N: BYD1-UP; CXK1-UP)

930H (S/N: DHC1-UP; FTD1-UP)

938H (S/N: MCC1-UP; MJC1-UP; JKM1-UP; LKM1-UP)

Wheel Tractor Scraper

613G (S/N: ESB1-UP; YCB1-UP; DBE1-UP)

Wheeled Excavator

M313D (S/N: J3A1-UP; K3D1-UP; W3H1-UP)

M315D (S/N: J5B1-UP; K5E1-UP; W5M1-UP)

M315D2 (S/N: CH31-UP)

M316D (S/N: W6A1-UP; P6K1-UP; D6W1-UP)

M317D2 (S/N: CH51-UP)

M318D (S/N: P8L1-UP; W8P1-UP; D8W1-UP)

M318D MH (S/N: P9M1-UP; W8R1-UP; D9X1-UP)

M322D (S/N: W2S1-UP; P2T1-UP; D2W1-UP)

M322D MH (S/N: W2T1-UP; P3W1-UP; D3X1-UP)

Introduction

There have been isolated occurrences of excessive fuel leakage past the electronic unit injectors on some engines.

Accelerated wear on the delivery valve results in an increased leak rate.

For six cylinder engines, the fuel injection pump cannot generate enough fuel flow or volume to compensate for the leak-off rates above a critical value of 38 mL (1.3 oz) per 30 seconds of cranking at a speed of 150 rpm.

For four cylinder engines, the critical value is 25 mL (0.85 oz) per 30 seconds of cranking at a speed of 150 rpm.

If the engine turns over but the engine does not start, refer to Troubleshooting, "Engine Cranks but Will Not Start". Perform the following procedure when directed by Troubleshooting, "Engine Cranks but Will Not Start". The procedure will help to assess the amount of fuel pressure leak-off within the high-pressure fuel system.

Note: The engine may start, but you may still have high leak-off within the high-pressure fuel system.

Note: If the electronic unit injectors are replaced, ensure that the valve bridge is seated in the correct position. Failure to carry out this procedure correctly may result in engine failure. For further information, refer to Engine News, SEBD9574, "Improved Valve Bridges" and Service Magazine, SEPD0975, "Improved Valve Bridges".

Note: If applicable, a completed service report (form number 089479-00) must be included with the returned parts. ECM warranty report downloads, datalogs, and any special test results as directed by repair procedures are to be uploaded to SIMS. Checklists that are packaged with replacement parts are to be completed and packaged with parts being returned.

Refer to Special Instruction, REHS7790, "Improved Fuel System Diagnostic Test Documentation for Certain C4.4 and C6.6 Engines" for additional diagnostic test documentation.

Test Procedure for Measuring High Leak-off for the Electronic Unit Injectors

Note: Caterpillar recommends that the procedure should be carried out without starting the engine.

1. Ensure that the engine is shut down. Remove the banjo bolt that is on the bottom of the fuel transfer pump.
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   Illustration 1	g01402111
   Typical example

2. Install Tooling (A) to the fuel transfer pump.

   Note: Tooling (A) will replace the banjo bolt that was removed in Step 1. Do not substitute Tooling (A). Tooling (A) is specially designed for the test.

3. Install a clear plastic hose (1). Place the opposite end of the plastic hose into a suitable container that is clean.

4. Connect the electronic service tool to the diagnostic connector.

5. Disconnect the three harness connectors for the electronic unit injectors at the valve mechanism cover base to prevent starting the engine.

6. Perform a data log of the following parameters at a sample rate of 240 samples per minute.

   ECM Parameters

   • Active Diagnostic Codes that are present

   • Atmospheric Pressure

   • Battery Voltage

   • Delivered Fuel Volume

   • Desired Engine Speed

   • Desired Fuel Rail Pressure

   • Diagnostic Clock

   • Engine Coolant Temperature

   • Engine Oil Pressure

   • Derate of Engine Power

   • Engine Speed

   • Fuel Rail Pressure

   • Inlet Air Temperature

   • Intake Manifold Pressure

   • Requested Desired Engine Speed

   • Fuel Volume for the Smoke Limit

   • Fuel Volume for the Torque Limit

   • Engine Load Factor
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   NOTICE
   After 30 seconds of cranking the engine, release the starter switch or button and wait 2 minutes to allow the starting motor to cool before attempting to start the engine again.

7. Start the data log. Crank the engine for 30 seconds.

8. End the data log.

9. Record the amount of fuel that has been collected in the container from the leak-off connector on the cylinder head. Conduct the test three times. Calculate the average of the three values.

10. Refer to step 10.a or step 10.b for the relevant values for your engine.

    1. For six cylinder engines, if more than 38 mL (1.3 oz) of fuel has been collected during the 30 second crank test, then there is high leak-off of the electronic unit injectors.

       For six cylinder engines, if less than 38 mL (1.3 oz) of fuel has been collected for the 30 second crank test, then there is not high leak-off of the electronic unit injectors.

       Refer to Troubleshooting, "Engine Cranks but Will Not Start" to diagnose the problem.

    2. For four cylinder engines, if more than 25 mL (0.85 oz) of fuel has been collected during the 30 second crank test, then there is high leak-off of the electronic unit injectors.

       For four cylinder engines, if less than 25 mL (0.85 oz) of fuel has been collected for the 30 second crank test, then there is not high leak-off of the electronic unit injectors.

       Refer to Troubleshooting, "Engine Cranks but Will Not Start" to diagnose the problem.

11. Remove Tooling (A). Install the banjo bolt and two new washers to the fuel transfer pump. Tighten the banjo bolt to a torque of 21 N·m (186 lb in).

12. End of the test. If there is high leakage of the high-pressure fuel system, proceed to "Measuring the Fuel Injection Pump Flow and High Leak-off for the Individual Electronic Unit Injector".

Measuring the Fuel Injection Pump Flow and High Leak-off for the Individual Electronic Unit Injector

This procedure provides a method to evaluate the internal leakage condition of the following components:

• Fuel injection pump

• Fuel pressure relief valve

• Electronic unit injectors

The procedure provides a method to compare internal fuel leakage to a precision calibrated orifice.

Use the"Test Kit Data Sheet" to record the test data. For an example of the test process calculations refer to "Example Calculations Sheet".

Use the checklist form provided with the replacement component to document the test results.

Do not discard this form. A completed checklist is required with the claim story. A completed checklist is to be included with any fuel injection system component returned for credit.

Use the following procedure to aid in the diagnosing of the following conditions:

• The engine cranks but the engine does not start

• The fuel rail pressure is low

• There has been a low rail-pressure event

• The engine fuel injection system has excessive internal fuel pressure leakage

Verify the following before continuing with this procedure:

• No fuel injection pump or electronic unit injector diagnostic trouble codes are active

• No external high-pressure leaks exist

• The cranking speed of the engine is at least 150 rpm

Note: A battery booster is essential to maintain consistent cranking speed of at least 150 rpm for all fuel injection pump and electronic unit injector tests.

• The low-pressure fuel system is providing a minimum of 50 kPa (7 psi) of pressure to the fuel injection pump.

Determine if the pressure in the fuel manifold (rail) during engine cranking is less than 22 MPa (3200 psi). This will assist when conducting the procedure in Troubleshooting, "Engine Cranks but Will Not Start".

If troubleshooting for low rail-pressure event, first warm up the engine to improve the test results.

• If possible run at high speed and load to duplicate the low rail-pressure event conditions

• If it is not possible to put load on engine, run the "Fuel System Verification Test". This will increase the desired rail-pressure to help get the fuel injection pump and electronic unit injectors warm.

• Proceed with the test procedure when the fuel injection pump and electronic unit injectors are still warm.

Required Parts

Illustration 2	g03019476
Typical example of 362-9754 Test kit (1) 356-2466 Case (2) 356-2470 Cylinder – Collection (3) 362-9749 Orifice As - Discharge (4) 362-9753 Pin - Gauge (5) 362-9751 Plug As - Rail

Test Procedure

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Electrical Shock Hazard. The electronic unit injectors use DC voltage. The ECM sends this voltage to the electronic unit injectors. Do not come in contact with the harness connector for the electronic unit injectors while the engine is operating. Failure to follow this instruction could result in personal injury or death.

Note: The pressures generated during this test are lower than those generated during normal operation. During this test, the fuel injection lines may be removed and reused when performing this procedure due to the lower pressures that are generated during the testing. This is the only condition where reuse of a fuel injection line is allowed.

Note: All connections must be clean prior to assembly. Carefully inspect all connections, caps, and lines before each use. When not in use, caps, plugs, and orifice from the kit must be capped to prevent damage and debris entry.

Use the gauge pin and an aerosol cleaner to ensure that the orifice is clean before performing this procedure.

Measure the Pressure of the Fuel Injection Pump

This part of the process will set up the test components and determine if the fuel injection pump or the fuel pressure relief valve is defective for internal leakage.

1. Obtain the Test Kit Data Sheet. Use the Test Kit Data Sheet to record all test measurements.

2. Remove the fuel injection lines. Refer to Disassembly and Assembly, "Fuel Injection Lines - Remove" for the correct procedure.
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   Illustration 3	g03017858
   Typical example

3. Connect one of the fuel injection lines (1) to the fuel manifold (rail) at cylinder number 1 fuel outlet connection. Connect the discharge orifice assembly (2) to the other end of the fuel injection line. Install the rail plug assemblies onto the fuel manifold (rail) for all remaining cylinder fuel outlet connections.

   Note: The collecting cylinder must be mounted at a position lower than the fuel manifold (rail) on the engine.

4. Insert the drain hose (3) from the outlet of the discharge orifice assembly into the collecting cylinder. Refer to Illustration 3.

5. Disable all electronic unit injectors by disconnecting the injector harness connectors. Leave the electronic unit injectors disabled for the duration of the test.
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   Illustration 4	g03017878
   Typical example

6. Set 240 samples/minute for the electronic service tool graphing utility, "Data Log Recorder".

7. Record the fuel pressure in the fuel manifold (rail) and engine speed while cranking for 10 seconds.

   Note: Make sure that there are no connection leaks during this test as the measurement will be invalid.

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   Illustration 5	g03017918
   Typical example (1) Pump test pressure measured at peak (2) Pump test engine speed measured when peak pressure occurs (3) 2 to 5 second typical for pressure to build (4) More than 5 seconds with pressure build required to capture peak

8. Determine the fuel pressure in the fuel manifold (rail) and the engine speed where the peak pressure was selected. Typically, pressure will start building after 2 to 5 seconds and then there should be samples taken for 5 more seconds. Illustration 5 shows an example of selecting the peak pressure and corresponding speed.

9. Use the engine speed where the fuel pressure in the fuel manifold (rail) was selected from Step 8 to determine the Minimum Cranking Pressure (MCP). Refer to Table 4 for engine size and cranking rpm.
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   Table 4

   Fuel Injection Pump MCP (Minimum Cranking Pressure)
   Engine Speed (rpm)	150-174	175-199	200-224	225-249	250-274	275-300
   Minimum Cranking Pressure for six cylinder engines	9391 kPa (1362 psi)	11935 kPa (1731 psi)	14713 kPa (2134 psi)	17713 kPa (2569 psi)	20926 kPa (3035 psi)	24352 kPa (3532 psi)
   Minimum Cranking Pressure for four cylinder engines	5550 kPa (805 psi)	6729 kPa (976 psi)	7970 kPa (1156 psi)	9253 kPa (1342 psi)	10583 kPa (1535 psi)	11956 kPa (1734 psi)

10. If the fuel pressure in the fuel manifold (rail) is less than the Minimum Cranking Pressure (MCP), inspect the Pressure Relief Valve (PRV) for leakage and retest. The PRV can be checked for leakage by inspecting the outlet of the valve for any fuel leakage. Refer to Special Instruction, REHS5712, "Checking the High-Pressure Relief Valve for Leakage" for the correct procedure.

11. If the PRV does not leak, and fuel pressure in the fuel manifold (rail) displayed in the electronic service tool graph is less than the MCP, remove, clean, and inspect the outlet check valves and retest. Refer to Special Instruction, REHS3751, "Servicing the Outlet Check Plugs on the Fuel Injection Pump" for the correct procedure.

12. Determine the new MCP based on the retest speed. If the fuel pressure in the fuel manifold (rail) displayed in the electronic service tool graph is still less than MCP, replace the fuel injection pump. Refer to Disassembly and Assembly, Fuel Injection Pump - Remove and Disassembly and Assembly, Fuel Injection Pump - Install for the correct procedures.

13. If the fuel pressure in the fuel manifold (rail) is greater than MCP, record the fuel pressure in the fuel manifold (rail) and peak pump rail pressure engine speed, which will be used for injector testing. Proceed to "Measure Electronic Unit Injector Leakage" section.

    Note: Do not remove the test kit. The test kit is required for the remainder of this procedure.

Measure Electronic Unit Injector Leakage

This part of the procedure will determine if individual electronic unit injectors are defective for internal leakage.

Note: The electronic unit injectors can be checked for leakage in any order, use the order that is best suited to your engine application.

Note: If the test speed for the electronic unit injector changes by more than 25 rpm from the measurement of Pump Test speed or drops below 150 rpm, a battery booster must be used to maintain uniform speed with the Pump Test. Maintaining a uniform cranking speed will improve the accuracy of test results. Make sure that there are no leaks during the test as the measurement will be invalid.

Note: When half or more of the electronic unit injectors are found to have excessive leakage, stop the test. Record the results of the leak rate for each electronic unit injector tested. Then replace all electronic unit injectors. Refer to Disassembly and Assembly, Electronic Unit Injector - Remove and Disassembly and Assembly, Electronic Unit Injector - Install for the correct procedures.

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Illustration 6	g03018160
Typical example

1. Install an existing fuel injection line for the cylinder you have selected. Refer to Disassembly and Assembly, "Fuel Injection Lines - Install" for the correct procedure. Ensure that all outlets from the fuel manifold (rail) are capped. Refer to Illustration 6.

2. Record fuel rail pressure and engine speed with the electronic service tool "Data Log Recorder" while cranking for 10 seconds.

   Note: Make sure that there are no connection leaks during this test as the measurement will be invalid.

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   Illustration 7	g03019497
   Typical example (1) Injector test pressure measured at peak (2) Injector test engine speed measured when peak pressure occurs (3) 2 to 5 second typical for pressure to build (4) More than 5 seconds with pressure build required to capture peak

3. Determine the fuel rail pressure and the injector test engine speed (where the peak pressure was selected). Typically, pressure will start building after 2 to 5 seconds and then there should be sampling for 5 more seconds. Illustration 7 shows an example of selecting the peak pressure and corresponding speed.

4. Calculate the speed change of the injector test as follows:

   Injector test speed change equals injector test engine speed minus pump test engine speed.

5. Determine injector pressure correction using the injector test speed change and Table 5. This will correct for pressure change as speed changes.
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   Table 5

   Injector Pressure Correction Based on Speed Change
   Engine speed change (rpm)	0-5	6-10	11-15	16-20	21-25	26-30	31-35
   Six-cylinder pressure correction	283 kPa (41 psi)	896 kPa (130 psi)	1455 kPa (211 psi)	2013 kPa (292 psi)	2572 kPa (373 psi)	3130 kPa (454 psi)	3689 kPa (535 psi)
   Four-cylinder pressure correction	159 kPa (23 psi)	510 kPa (74 psi)	834 kPa (121 psi)	1151 kPa (167 psi)	1469 kPa (213 psi)	1793 kPa (260 psi)	2110 kPa (306 psi)

6. If the injector test engine speed is lower than pump test engine speed, then correct the injector pressure by adding the correction as follows:

   Injector corrected pressure equals injector test pressure plus injector pressure correction.

7. If the injector test engine speed is higher than pump test engine speed (as can happen when a battery booster is used), then correct the injector test pressure by subtracting the pressure correction as follows:

   Injector corrected pressure equals injector test pressure minus injector pressure correction.

8. Calculate injector leakage ratio as follows:

   Injector leakage ratio equals injector corrected pressure divided by pump test rail pressure.

   If the Injector leakage ratio is less than 0.85, the injector must be replaced, if the injector leakage is greater than 0.85 the injector is within the required parameters.

   Remove the fuel line. Replace the cap on the fuel manifold (rail) and injector.

9. Proceed to the next injector to be checked. Repeat Step 1 through Step 8 for the remaining electronic unit injectors to be tested.

10. Remove components of 362-9754 Test Kit from the engine. Replace any fuel injection lines that were removed during the procedures. Refer to Disassembly and Assembly, Fuel Injection Lines - Install for the correct procedure.

11. Reconnect the electronic unit injector harness connectors.

Test Kit Data Sheet

Example Calculations Sheet

Fuel Injection Pump Test

Illustration 8	g03019697
Typical example of pump pressure and speed measurement

Pump Test Rail Pressure (1) is 14148 kPa (2052 psi). Pump Test Engine Speed (2) is 162 rpm.

With Pump Test Engine Speed of 162 rpm, Minimum Cranking Pressure (MCP) from table 4 is 9391 kPa (1362 psi).

Pump Test Rail Pressure of 14148 kPa (2052 psi) is larger than MCP of 9391 kPa (1362 psi), so fuel injection pump is OK.

Electronic Unit Injector Test

Illustration 9	g03019781
Typical example of injector Test pressure and speed measurement

Injector Rail Pressure (1) is 10721 kPa (1555 psi). Injector Test Engine Speed (2) is 144 rpm.

Injector Engine Speed Change is 162 minus 144 equals 18 rpm.

Injector Pressure Correction from table 5 is 2013 kPa (292 psi).

Speed is higher than pump test speed so add the correction: Injector Corrected Pressure equals 10721 kPa (1555 psi) add 2013 kPa (292 psi) equals 12735 kPa (1847 psi).

Injector Leakage Ratio is 1847 divided by 2052 equals 0.90.

Injector Leakage Ratio of 0.90 is larger than injector ratio threshold of 0.85, so the injector leakage is OK.