RAM 3500 Chassis Cab Truck 2WD L6-6.7L DSL Turbo (2010)
Fuel Pressure: Testing and Inspection
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
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Go To 12
No
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Replace the failed Fuel Injector(s) and verify repair by performing the High Pressure Fuel System test procedure with the scan tool again.
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Perform the POWERTRAIN VERIFICATION TEST - 6.7L. See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble
Code Tests and Associated Procedures/Verification Tests/Powertrain Verification Test.
12. HIGH PRESSURE DELIVERY PUMP RETURN FLOW TEST
1. Turn the engine off.
