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Home >> Dodge or Ram Truck >> 2010 >> RAM 3500 Chassis Cab Truck 4WD L6-6.7L DSL Turbo >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> Checking the Fuel Delivery System >> Part 2

Part 2






CHECKING THE FUEL DELIVERY SYSTEM

For a complete wiring diagram, Refer to the Wiring Information

11. ENGINE RUNNING INJECTOR RETURN FLOW TEST

NOTE: The purpose of this test is to determine if the Fuel Injectors are leaking internally into the fuel return.

1. Turn the engine off.
2. Remove fuel system test fitting 9012 from the Pressure Limiting Valve.
3. Operate the engine until the coolant temperature is above 82.2°C (180°F).
4. Turn the engine off.
5. Remove the banjo connector from the fuel drain tube at the rear of the fuel filter housing.
6. Install fuel system test fitting 9012 in place of the banjo connector.

NOTE: Do not use test fitting 9014. This fitting will block return flow from the High Pressure Delivery Pump and damage the seal and could potentially damage the engine.

7. Install a 5/16 diameter rubber fuel hose (Hose A) onto the test fitting and into a fuel container.

NOTE: This hose will be used to measure the High Pressure Pump return flow in the next test procedure.

8. Remove the vehicle fuel return line (Quick connect) from the engine fuel drain tube.
9. Install a 5/16 diameter rubber fuel hose (Hose B) onto the engine fuel drain tube and into the fuel container.

NOTE: This hose will be used to measure the Injector return flow for this procedure.

10. Start engine and allow to idle for 30 seconds. This step allows the flows to stabilize.
11. Using the scan tool, navigate to ECM view -> PCM Cummins -> More Options-> System Tests -> Fuel Pressure Override Test. Select Start, then press Next.

NOTE: While the test is running, record the FCA duty cycle % and actual rail pressure.

12. As you press the Run button to start the Fuel Pressure Override Test, move (Hose B) from the bucket and insert it into a graduated cylinder. The engine speed will elevate rapidly to 1200 RPM and the rail pressure will increase to 26107 psi (1800 bar). Collect the fuel until the Fuel Pressure Override Test times out (30 seconds).
13. Measure and record the amount of fuel collected in the graduated cylinder. Repeat this three times and take the average of the three results.

NOTE: Flow should be less than 210 ml for 30 seconds.

14. If the flow is less than 210 ml/30 seconds, the test has successfully passed. If the flow is greater than 210 ml/30 seconds, turn off the engine and remove all 6 high pressure fuel lines. Re-torque the high-pressure connector nut for each injector. Inspect for damage, repair/replace as necessary. Reinstall the high pressure fuel lines. Re-measure the injector return flow using steps 10 through 13 as a guide. Continue on to next step.
15. If the amount of fuel is still greater than 210 ml/30 seconds after re-torquing the high-pressure connector nuts, turn the engine off and remove the #1 high pressure fuel line. Cap the #1 fuel port using tool 9864 for the 6.7L engine on the fuel rail and re-measure the injector return flow using steps 10 through 13 as a guide. Repeat this procedure for injectors 2-6. Continue on to next step.
16. Replace the Fuel Injector and High pressure connector of the injector that shows the largest amount of change when capped off.

Did the vehicle pass the Injector Return Flow test at step 13 without any repairs needed?

Yes

- Go To 12

No

- Replace the failed Fuel Injector(s) and verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

12. HIGH PRESSURE DELIVERY PUMP RETURN FLOW TEST
1. Turn the engine off.
2. Remove fuel system test fitting (9012) from the fuel drain tube at the rear of the fuel filter housing.
3. Reconnect the drain tube.
4. Start the engine and let it idle for one minute.
5. Measure the amount of fuel collected from (Hose A) in the graduated cylinder.
6. The fuel flow should be less than 1,000 ml/minute at idle.

Is the flow less than 1,000 ml/minute at idle?

Yes

- Go To 13

No

- Replace the High Pressure Delivery Pump. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

13. HIGH PRESSURE DELIVERY PUMP PERFORMANCE TEST
1. Disconnect the Fuel Control Actuator harness connector.
2. Disconnect high pressure fuel line from the fuel rail and route the high pressure fuel line into a graduated cylinder.
3. Crank the engine until fuel exits this line. This will not be high pressure fuel.
4. Empty the fuel and crank the engine for three 10 second intervals.

NOTE: This will give you 30 total seconds of flow time. These are broken into three separate intervals to prevent damage to the starter.

5. Fuel flow specification's based on engine cranking speed. If you do not collect the stated amount of fuel in 30 seconds, replace the pump:
- Minimum fuel pump flow at 150 RPM cranking speed is 70 ml.
- Minimum fuel pump flow at 200 RPM cranking speed is 90 ml.

Does the fuel flow exceed the minimum specification?

Yes

- Go To 14

No

- Replace the High Pressure Delivery Pump. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

14. CHECKING THE FUEL CONTROL ACTUATOR
1. Reconnect the Fuel Control Actuator harness connector.
2. Reconnect all fuel lines and hoses.
3. Start the engine.
4. With the scan tool, navigate to Systems Tests and select the Fuel Pressure Override Test.
5. Allow the engine speed and fuel pressure to ramp up and stabilize and then stop actuation.

Does the engine speed and fuel pressure ramp up and stabilize when actuated and then come back to rest at idle and stabilize when actuation is stopped?

Yes

- The fuel system is experiencing an intermittent condition. Check for any Service Bulletins that may apply.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the Fuel Control Actuator. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

15. PRESSURE LIMITING VALVEPRESSURE LIMITING VALVE (NO START)





NOTE: In the illustration provided, the pressure-limiting valve location is indicated by the number (1).

1. Turn the engine off.
2. Reconnect the fuel supply hose.
3. Remove the banjo bolt from the Pressure Limiting Valve on the fuel rail.
4. Install fuel system test fitting 9012 into the Pressure Limiting Valve.
5. Attach one end of a fuel hose to the fuel fitting and put the other end of the fuel hose into a container.
6. Crank the engine and look for fuel leaking from the Pressure Limiting Valve.

NOTE: There should be no fuel flow into the container.

Is fuel flowing into the container?

Yes

- Replace the Pressure Limiting Valve. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 16

16. INJECTOR RETURN FLOW TEST DURING ENGINE CRANKING @ 200 RPM (NO START)
1. Remove fuel system test fitting 9012 from the Pressure Limiting Valve.
2. Remove the banjo connector from the fuel drain tube at the rear of the fuel filter housing.
3. Install fuel system test fitting 9012 in place of the banjo connector.

NOTE: Do not use test fitting 9014. This fitting will block return flow from the High Pressure Delivery Pump and damage the seal and could potentially damage the engine.

4. Install a 5/16 diameter rubber fuel hose (Hose A) onto the test fitting and into a fuel container.

NOTE: This will be used to measure the High Pressure Pump return in the next test procedure.

5. Remove the vehicle fuel return line (Quick connect) from the engine fuel drain tube.
6. Install a 5/16 diameter rubber fuel hose (Hose B) onto the engine fuel drain tube and into the fuel container. Make sure test lines are straight and slope downward their entire length. This is to avoid trapping air/fuel in the lines while testing.

NOTE: This will be used to measure the Injector return flow for this procedure.

7. Unplug the injector harnesses at the valve cover, unplug the harness connector to the FCA.
8. Crank the engine for least 10 seconds until fuel starts to flow out of the pump and injector return hoses. Turn Key off when finished.
9. Let all the fuel drain out of each line before continuing.
10. Place (Hose B) into a graduated cylinder.
11. Crank the engine for 10 seconds (Go from Key off to Crank back to Key off). Do not leave the ignition on between tests.
12. Let all of the fuel drain out of the injector hose.
13. Record the amount of injector return flow for a 10 second crank.

NOTE: Flow should be less than 40 ml for 10 seconds of cranking.

14. If the flow is less than 40 ml, the test has successfully passed. If the flow is greater than 40 ml, remove all 6 high pressure fuel lines and re-torque the high-pressure connector nut for each injector. Inspect for damage, repair/replace as necessary. Reinstall the high pressure fuel lines. Re-measure the injector return flow using steps 7 through 12 as a guide. Continue on to next step.
15. If the amount collected is still greater than 40 ml, remove the #1 high pressure fuel line. Cap the #1 fuel port using tool 9864 for the 6.7L engine on the fuel rail and re-measure the injector return flow using steps 7 through 12 as a guide. Continue on to next step.
16. If the amount collected is less than 40 ml for 10 seconds after capping the #1 fuel port, remove and replace the #1 Fuel Injector and #1 High pressure connector. If the amount of fuel collected is still greater than 40 ml after capping the #1 fuel port, repeat step 14 for injectors 2-6.

Did the vehicle pass the Injector Return Flow test at step 13 without any repairs needed?

Yes

- Go To 17

No

- Perform the necessary repair. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

17. HIGH PRESSURE DELIVERY PUMP PERFORMANCE TEST (NO START)
1. Turn the engine off.
2. Disconnect fuel line and the fuel system test fitting 9012.
3. Reconnect the banjo connector to the drain tube.
4. Disconnect the FCA harness connector.
5. Disconnect high pressure fuel line from the fuel rail and route the high pressure fuel line into a graduated cylinder.
6. Crank the engine until fuel exits this line. This will not be high pressure fuel.
7. Crank the engine for three 10 second intervals.

NOTE: This will give you 30 total seconds of flow time. These are broken into three separate intervals to prevent damage to the starter.

8. Fuel flow specification's based on engine cranking speed. If you do not collect the stated amount of fuel in 30 seconds, replace the pump:
- Minimum fuel pump flow at 150 RPM cranking speed is 70 ml.
- Minimum fuel pump flow at 200 RPM cranking speed is 90 ml.

Does the fuel flow exceed the minimum specification?

Yes

- The fuel system is operating normally. Check for any Service Bulletins that may apply.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Replace the High Pressure Delivery Pump. Verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

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