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catmastertech, Technician
Category: Construction and Road Equipment
Satisfied Customers: 2334
Experience:  Field service technician for CAT 19 years.
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I have a 336EL with C9.3. Connected with ET found logged

Customer Question

I have a 336EL with C9.3. Connected with ET found logged event code E499 (3) Fuel Rail #1 Pressure Leak, no active codes, trouble shot code with SIS, checked for associated codes, no associated codes, performed warranty download and product status report, inspected the fuel system found fuel filter leaking, installed new fuel filter, checked the fuel rail sensor, allowed the engine to be off for 10 minutes, turned the key switch to the on position, connected to the engine ECM using Cat ET, checked the status of the "Fuel Rail Pressure (absolute)" rail pressure went from 10,683 psi to 0 psi, very quickly. Performed fuel system functional test, passed pre test failed main test, Torque all the quill tubes again, then perform the Fuel System Functional Test, test failed, performed Injector Bypass Fuel flow test, got(###) ###-####Test Kit from tool room, disconnected high-pressure fuel line from the high-pressure fuel pump, connected pump to drain hose to the high-pressure fuel pump, routed the hose to a graduated cylinder, cranked the engine for 20 seconds and recorded the fuel volume of 7 ounces, test spec was minimum 1.4 ounces, measured rail pump pressure, removed the fuel lines for the injectors,, Installed the injector plug assemblies on the rail for cylinders 1, 3, 4, 5, and 6, Installed the orifice assembly on port 2, disconnected the 12-pin connector. Used ET to record the maximum pressure of the fuel rail while the engine cranks for 10 seconds. RPM was248 and fuel rail pressure was 3669psi, minimum rail pressure spec was 1488psi. Proceeded to "Measure the Leakage for Injectors'' #3, 6,194psi #4, 5,912psi #5 5,894psi #6 5,797psi #1 5,840psi #2 5,989psi. Calculated leakage all within spec. Torque quill tubes to 52 ft lbs, installed injector fuel lines, performed fuel system functional test, passed pre test failed main test. Contacted TC.TC advised ''The only check valves are the outlets for both plungers in the pump. The code is telling us that the line leaks down in between pumping cycles. It should stay pressurized since the checks in the main pump should not let fuel back in the pump and the injectors are closed.This is an event and should not send out that code. Clear all of the faults and operate the machine. Then send me a new psr off the machine with the new faults on the machine.'' I cleared the codes took it out back and dug a hole with it and ‘’Engine Fault Shut down Safely’’ and the buzzer went off within about 15 minutes of run time.
Submitted: 1 year ago.
Category: Construction and Road Equipment
Customer: replied 1 year ago.
I've replaced the injector pump and transfer pump comes with it, fuel rail pressure sensor, pressure relief valve on the other end of the rail, removed check valve for the fuel return cleaned tested and reinstalled, replaced Pressure regulator for the drain line.
Expert:  catmastertech replied 1 year ago.


Can you upload a pdf copy of the PSR and include the machine's serial number?

All sensors that have the "Absolute" value compare pressures using the Atmospheric pressure sensor as a base reference. Have you tested the Atmospheric pressure sensor? ( I am not certain this is related but, I have seen strange things happen when it is not working.)

Have you performed the "Fuel System Verification Test"?

Expert:  catmastertech replied 1 year ago.

What failure codes you are getting when the Fuel System Functional Test fails?

Expert:  catmastertech replied 1 year ago.

Were the injectors replaced recently? How many hours are on the injectors?

Expert:  catmastertech replied 1 year ago.

Ohh! Wait!! I remember were I had problems here too.

You should not get pressures higher than the baseline result. You must install the drain orifice in one of the other ports (use # ***** since it is the last one checked) and then perform the leakoff test. You will get the correct results then.

If the TC tells you the same thing he told me, this test is inconclusive and replace the injectors anyway!

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