CAT 320D Excavator
was found to have a side turn due to snow road slide.The C6.4 type engine installed inside stopped automatically.After overhauling the engine,it was found that it could not start and the exhaust pipe did not smoke.Now we use ET (a software used on PC to detect the engine's working state and parameters) to measure and find that starting speed was measured at 202r/min, the fuel pressure was 3.1mpa,and the primary and secondary timing sensors were normal.When the ignition switch is turned on, ET shows that the fuel injection status is prohibited. After the engine is driven by tools, the fuel injection status still cannot be turned on.
There might have three reasons for the failure of the fuel injection:
1.Control line or ECM (electric control module) of engine have problem
2.Engine oil pressure is lower than normal
3.Engine timing error
We checked above three reasons one by one, but the results still keep same.
Then we have to change our method.Test the injector solenoid valve with ET, and all the solenoid valves are on and off normally.ET was used to measure the pressure of the common rail injector is 3.1mpa, which indicated that the high-pressure pump could provide the common rail injector with normal pressure fuel, but the engine ECM did not send the fuel injection signal.Meanwhile after checking,we also find that the engine ECM is normal and the sensor is also normal,so it is speculated that the signal collected by the sensor is wrong.Thus, remove the main timing sensor on the flywheel housing of the engine while keep only the secondary timing sensor of the high-pressure pump.At this moment, there was smoke coming out of the exhaust pipe, but the engine was still unable to start.From this we judge, probably that high pressure pump timing is wrong.
When the high-pressure pump is removed, it's difficult to turn.By further inspection, it was found that the semicircular keys on the camshaft of the high pressure pump were cut off, causing a dislocation of the position of the camshaft relative to the driving gear.Repair the pump and try again,the engine starts normally.