what is best scanner to use to test high pressure? I have a snap on brick but its not updated new enough, should not of gotten rid of my brick with black cartridges good to 06...
I read that some scanners will work on some years, but not others, any that work on all years... . I've been thinking of purchasing a new scanner and don't want to buy multiple if not needed. I have done lots of work on VP44 trucks but limited on CR, many injectors in 06 trucks... .
also this 03 loses lift pump pressure within a couple minutes of being shut off, my 99(old reliable) holds pressure after shut down... ????
As far as testing the high pressure output of the CP3 at this point, since it runs fine once started, is most likely not necessary. The rail pressure relief valve could be failing, that would account for hard starting for the same reason as loose cross tubes, CP3 cannot create enough pressure to fire injectors.
You need to conduct an injector fuel return rate test at the CP3 or at the rear of the head. Disconnect the fuel return line, attach a short hose and place in a clean jar, start the truck (ether if needed) let idle for 30 seconds shut off. Pour the fuel from the jar into a measuring cup capable of milliliters, The amount allowable IIRC should be under 80 ML, I do not have my notes here with me, someone else or your info may state the allowable return
EDIT: (allowable return, 1000prm with FCA unplugged for 30 seconds, 160 ML optimal, 240 ML bad news. ). If return is higher, the you have a failed pressure relief valve, leaking injector(s), or leaking cross tubes.
Since re-torquing the cross tubes does not require new parts, it is the first and foremost exercise to perform. If that does not solve the issue, next I would test the RPRV, disconnect the return line from the RPRV and bag it with a plastic sandwich bag and rubber bands. Then screw an adapter into the RPRV and bag it also, unplug the FCA harness, this allows max CP3 press. Start the truck momentarily and let idle for a few seconds and shut down. The truck will rattle like hell because of the high CP3 pressure, if any fuel has escaped the RPRV into the sandwich bag, the valve is kaput. The return line bag will have some fuel in it.
After these test have been performed and issues still persist, then injectors may be considered... let us know your outcome.
Jess
The lift pump pressure leaking off at shutdown is normal for a CR.
Here is a better description for the fuel return rate test,
looks like this may be for a 6. 7, too much info out there.
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.
5. Install a 5/16 diameter rubber fuel hose (Hose A) onto the test fitting and into a fuel container.
NOTE: This hose is used to measure the High Pressure Pump return flow.
6. Remove the vehicle fuel return line (Quick connect) from the engine fuel drain tube.
7. 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.
8. Start engine and allow to idle for 30 seconds. This step allows the flows to stabilize.
9. 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. Record the readings on the Cummins DieselDiagnostic Worksheet located under e-files, service, Star center in Dealerconnect.
10. Press the Run button to start the Fuel Pressure Override Test. The engine speed will elevate rapidly to 1200 RPM and the rail pressure will increase to 20000 psi (1400 bar). At this point, move (Hose B) from the bucket and insert it into a graduated cylinder. Collect the fuel until the Fuel Pressure Override Test times out (30 seconds).
11. Measure and record the amount of fuel collected in the graduated cylinder.
NOTE: Flow should be less than 160 ml for 30 seconds.
NOTE: If the amount of fuel collected is greater than 240 ml/30 secs, it is recommended that all 6 injectors be replaced.
12. If the flow is less than 160 ml/30 seconds, the test has successfully passed. If the flow is greater than 160 ml/30 seconds, but less than 240 ml/30 secs, 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 8 through 12 as a guide. Continue on to next step.
13. If the amount of fuel is still greater than 160 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 8 through 12 as a guide. Repeat this procedure for injectors 2-6. Continue on to next step.
14. 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 12 without any repairs needed?
Yes
Injector return flow is within specification, and no repair is needed. Perform the FUEL PUMP RETURN FLOW TEST procedure. (Refer to 29 - Non-DTC Diagnostics/Drivability - Diesel - Diagnosis and Testing) .
No
Replace the failed Fuel Injector(s) and verify repair.
Perform the POWERTRAIN VERIFICATION TEST - 6. 7L. (Refer to 28 - DTC-Based Diagnostics/MODULE, Engine Control (ECM) - Standard Procedure).
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