3126B and 3126E On-highway Engines Caterpillar

Use the steps that follow to check the operation of the HEUI fuel system. Circle the appropriate answer in the Results section of each step. Complete the pages. Return the pages with any of the requested parts through the part return system.

Illustration 1	g00725749
HEUI fuel system components (typical example)

Test Step 1. Symptoms

The following symptoms may occur if there is a problem with the HEUI fuel system:

• The engine cranks but the engine will not start.

• The engine runs rough.

• The engine is erratic or unstable at idle or running.

• Low power

• The following fault codes might be currently active codes or logged event codes: 164-00, 164-02 and 164-11.

Complete the following test steps. Circle the appropiate answers in the Results section of each test step and return with the fuel system component.

1. Connect the electronic service tool to the service tool connector.

2. Turn the ignition keyswitch to the ON position but do not start the engine.

3. Print the "Lifetime Totals" and the "Configuration" screen.

4. Check for active diagnostic codes.

Expected Result:

There are no active diagnostic codes with the keyswitch in the ON position and the engine off.

Results:

• OK - There are no active codes. Proceed to Test Step 2.

• Not OK - Active codes are present with the keyswitch in the ON position and the engine off.

  Repair: Refer to Troubleshooting, "Injection Actuation Pressure Sensor - Test" if 164-03 or 164-04 is active.Call technical support if 164-00, 164-02, or 164-11 is active.

  STOP

Test Step 2. Check the Engine Oil Level

1. Check the engine oil level.

2. If the engine oil level is low add oil to the engine.

3. Try to start the engine.

Expected Result:

The engine starts.

Results:

• Yes - The engine starts. Proceed to Test Step 9.

• No - The engine does not start. Proceed to Test Step 3.

Test Step 3. Engine Cranks but Will not Start

Your answers indicated that your engine oil level is satisfactory. Do not replace the Injection Actuation Pressure Sensor (IAP Sensor) at this time.

1. Connect the electronic service tool to the engine. Observe the "Injection Actuation Pressure" and "Engine RPM" when the engine is cranking.

   ________ Record the actual Injection Actuation Pressure.

   ________ Record the observed engine speed.

Expected Result:

The injection actuation pressure is above 6 MPa (870 psi).

Results:

• Yes - The injection actuation pressure is above 6 MPa (870 psi).

  Repair: The HEUI system is functioning correctly. Refer to Troubleshooting, "Engine Cranks but Will Not Start" which is located in the "Troubleshooting without a Diagnostic Code" section.

  STOP

• No - The injection actuation pressure is below 6 MPa (870 psi). Proceed to Test Step 4.

Test Step 4. Check the Oil Pressure

Disconnect the high pressure oil line from the cylinder head and install the 8T-0852 Pressure Gauge. Crank the engine and record the oil pressure.

Note: The pressure readings may vary between gauges.

________ Observed pressure reading

________ Observed RPM

________ Observed "Injection Actuation Output Percent"

Expected Result:

The oil pressure is above 27.5 MPa (4000 psi).

Results:

• Yes - The oil pressure is above 27.5 MPa (4000 psi). Proceed to Test Step 8.

• No - The oil pressure is below 27.5 MPa (4000 psi). Proceed to Test Step 5.

Test Step 5. Install a Test Plug and Check the Oil Pressure

1. Remove the Injection Actuation Pressure Control Valve (IAPCV).

2. Install a 219-2368 Plug and 9X-1484 Seal Kit and perform the pressure test.

   ________ Observed pressure reading

   Note: If the 219-2368 Plug is not available, proceed to Test Step 6.

Expected Result:

The oil pressure is above 27.5 MPa (4000 psi).

Results:

• Yes - The oil pressure is above 27.5 MPa (4000 psi). The HEUI pump is OK.

  Repair: Replace the IAPCV and check the oil pressure. If the problem continues contact technical support.

  STOP

• No - The oil pressure is below 27.5 MPa (4000 psi). Proceed to Test Step 7.

Test Step 6. Install a New IAPCV and Check the Oil Pressure

Note: Use this Test Step ONLY if the 219-2368 Plug is not available.

1. Remove the IAPCV.

2. Install a new IAPCV and check the oil pressure.

   ________ Observed pressure reading

Expected Result:

The oil pressure is above 27.5 MPa (4000 psi).

Results:

• Yes - The problem has been resolved.STOP

• No - Remove the new IAPCV and reinstall the original IAPCV. Proceed to Test Step 7.

Test Step 7. Check the Drive Gear

1. Remove the high pressure oil pump.

2. Check for any physical damage to the drive gear. Replace the drive gear, if necessary.

3. Verify that the drive gear and the retaining bolt are properly tightened. Also verify that the pump shaft rotates freely.

Expected Result:

The drive gear and the retaining bolt for the high pressure oil pump are tight. The pump shaft rotates freely.

Results:

• Yes - The drive gear bolt is properly tightened and the pump shaft rotates freely.

  Repair: Replace the high pressure oil pump. If this does not fix the problem, contact technical support.

  STOP

• No - The pump shaft does not rotate freely.

  Repair: Replace the high pressure oil pump. If this does not fix the problem, contact technical support.

  STOP

• No - The drive gear bolt is loose. The pump shaft rotates freely and there is no obvious mechanical damage that would indicate a different failure.

  Repair: Tighten the drive gear bolt to a torque of 110 ± 14 N·m (80 ± 10 lb ft). Check the pressure in order to ensure that the problem has been resolved. If this does not fix the problem, replace the high pressure oil pump.

  STOP

Test Step 8. Check the High Pressure Oil System for Leaks.

Show/hide table

Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

1. Remove the valve cover and inspect the high pressure oil system for oil leaks.

2. While the engine is being cranked, look around the injector bores for any signs of oil leakage. Inspect the injector spill ports for excessive oil. All six injectors should spill the same amount of oil.

Expected Result:

No leaks are apparent.

Results:

• OK - Call technical support for assistance.STOP

• Not OK -

  Repair: Replace the O-ring on the injector or replace the damaged injector.

  STOP

Test Step 9. Engine Starts

1. Connect the electronic service tool to the engine and start the engine.

2. Check for the following codes:

• 164-00 Injection Actuation Pr Out of Range

• 164-02 Injection Actuation Pr Sensor Erratic

• 164-11 Injection Actuation Pressure System

Expected Result:

164-00 or 164-11 is active or logged.

Place a check beside the codes that are active or logged.

• ________ 164-00

• ________ 164-02

• ________ 164-11

Results:

• Yes - 164-00 or 164-11 is active or logged. 164-02 may also be active or logged. Proceed to Test Step 10.

• No - 164-02 is active or logged, but 164-00 and 164-11 are not active or logged.

  Repair: Refer to Troubleshooting, "Injection Actuation Pressure Sensor - Test" for information on troubleshooting the active 164-02 code.

  STOP

Test Step 10. Evaluate the Quality of the Oil

Extended oil drain intervals may cause elevated levels of soot in the engine oil. The elevated levels of soot may also deplete the additive package of the oil. This can affect the operation of the HEUI high pressure oil system.

Use the following formulas to calculate the correct oil change intervals. Scheduled oil sampling should be used to provide the most accurate oil change interval.

The formulas require information to be collected from the electronic service tool. Enter the values from the electronic service tool for "Total Distance" and "Total Fuel".

English

Total Distance ________ (miles)
/ Total Fuel ________ (gallons)
= Overall MPG ________
Overall MPG ________
X 50
X Oil Pan Capacity in Quarts ________
= Recommended Interval ________

Metric

Total Distance________ (kilometers)
/ Total Fuel ________ (liter)
= Overall KPL ________
Overall KPL ________
X 200
X Oil Pan Capacity in Liters ________
= Recommended Interval ________

Note: The recommended capacities for oil pans that follow are for truck engines.

• The capacity for the shallow oil pan is 21 L (22 qt).

• The capacity for the deep oil pan is 28 L (30 qt).

Record the drain interval that the owner is currently using.

________ Drain interval

________ Miles or Kilometers since the last oil change.

Expected Result:

The customer has not exceeded the suggested oil change interval and an oil change does not need to be performed.

Results:

• Yes - Proceed to Test Step 11.

• No - Before you proceed, ask the customer to authorize an oil change with a new oil filter. Oil changes are not covered by the warranty. After the engine oil and the oil filter have been changed, operate the engine until normal operating temperature has been reached. Run the engine up and down through the operating rpm range for 10 to 15 minutes. This will purge any trapped air or debris that is in the system. If the problem still exists or if the problem reoccurs in a short period or time, proceed to Test Step 11.

Test Step 11. Check the System with the "Injection Actuation Pressure Test"

1. Install 8T-0852 Pressure Gauge on the high pressure oil rail.

2. Connect the electronic service tool to the service tool connector.

3. Access the "Injection Actuation Pressure Test" in the "Diagnostics Menu" of the electronic service tool and begin the test.

   Note: The "Injection Actuation Pressure Test" can increase the injection actuation pressure or the "Injection Actuation Pressure Test" can decrease the injection actuation pressure. The test adjusts the oil pressure in steps. Depending on the interface which you are using, you may have either three steps or four steps.

   Show/hide table

   Table 1

   Step	Manual Pressure gauge	Electronic Service Tool	Difference
   1
   2
   3
   4

Expected Result:

The pressure that is measured with the pressure gauge for each step and the pressure that is displayed on the electronic service tool for each step are within 1379 kPa (200 psi).

Results:

• Yes - The injection actuation pressure sensor is operating properly. Proceed to Test Step 12.

• No - The injection actuation pressure sensor may be faulty. Replace the sensor and repeat this test step. If the problem still exists, verify the accuracy of the pressure gauge. Reinstall the original sensor and proceed to Test Step 12.

Test Step 12. Perform the "Injection Actuation Pressure Test" at both Low Idle and at High Idle

Start the engine. Run the "Injection Actuation Pressure Test" at low idle and at high idle.

Record the data in the following table.

Expected Result:

The "Injection Actuation Pressure Output" never exceeds 65% and never falls to 0 %.

Results:

• Yes - Call technical support for assistance.STOP

• No - Proceed to Test Step 13.

Test Step 13. Install a New IAPCV and Repeat the "Injection Actuation Pressure Test"

Replace the IAPCV and perform the "Injection Actuation Pressure Test".

Record the data in the following table.

Expected Result:

The "Injection Actuation Pressure Output" never exceeds 65% and never falls to 0 %.

Results:

• Yes - Verify that the problem is solved.STOP

• No - Reinstall the original IAPCV. Proceed to Test Step 14.

Test Step 14. Check the Oil Pressure

1. Turn the engine off.

2. Remove the Injection Actuation Pressure Control Valve (IAPCV).

3. Install a 219-2368 Plug and 9X-1484 Seal Kit and perform the pressure test.

4. Disconnect the high pressure oil line from the cylinder head and install the 8T-0852 Pressure Gauge. Crank the engine and record the oil pressure.

Note: The pressure readings may vary between gauges.

________ Observed pressure reading

________ Observed RPM

Expected Result:

The oil pressure is above 27.5 MPa (4000 psi).

Results:

• Yes - The high pressure oil pump is working properly. Proceed to Test Step 16.

• No - The high pressure oil pump may be faulty. Proceed to Test Step 15.

Test Step 15. Check the Drive Gear

1. Remove the high pressure oil pump.

2. Check for any physical damage to the drive gear. Replace the drive gear, if necessary.

3. Verify that the drive gear and the retaining bolt are properly tightened. Also verify that the pump shaft rotates freely.

Expected Result:

The drive gear and the retaining bolt for the high pressure oil pump are tight. The pump shaft rotates freely.

Results:

• Yes - The drive gear bolt is properly tightened and the pump shaft rotates freely.

  Repair: Replace the high pressure oil pump. If this does not fix the problem, contact technical support.

  STOP

• No - The pump shaft does not rotate freely.

  Repair: Replace the high pressure oil pump. If this does not fix the problem, contact technical support.

  STOP

• No - The drive gear bolt is loose. The pump shaft rotates freely and there is no obvious mechanical damage that would indicate a different failure.

  Repair: Tighten the drive gear bolt to a torque of 110 ± 14 N·m (80 ± 10 lb ft). Check the pressure in order to ensure that the problem has been resolved. If this does not fix the problem, replace the high pressure oil pump.

  STOP

Test Step 16. Check the High Pressure Oil System for Leaks

Show/hide table

Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.

1. Remove the valve cover and inspect the high pressure oil system for oil leaks.

2. While the engine is being cranked, look around the injector bores for any signs of oil leakage. Inspect the injector spill ports for excessive oil. All six injectors should spill the same amount of oil.

Expected Result:

No leaks are apparent.

Results:

• OK - Call technical support for assistance.STOP

• Not OK -

  Repair: Replace the O-ring on the injector or replace the damaged injector.

  STOP