hitachi 670 dramas

hi all .we have a number of hitachi machines. my latest headache. was a 670 zxlch3. it had issues stopping by itself over a fe weeks. we eventually tramped it back to the workshops .en route it died again and has not moved since. i put dr zx on it and amoug many faults found g sensor, crank sensor ,boost sensor issues .all these incl fuel pump changed as the local dealer reccomended the same. i also changed the main harness and caried out many repairs to the engine harness .there is no voltae appearig at the injectors . i saw a fault indicated as a rom failure ,have i a screwed ecm .. any advise welcome

IIRC there are control units behind the seat, under the tray on the ZX-3 units. I have seen a couple cases where water bottles or spray bottles of cleaner leak down and onto the controllers or connectors and cause issues over time.

Stupid question but did you check the fuel shutoff switch below the operator's seat, door side of the cab? Had a customer who had a machine down for 2 weeks during Christmas holidays due to that switch being flipped. Also check that the switch isn't sticking.

After you replaced all the parts did all the fault codes clear ok?

hi, thanks checked switch, cutoff ,shows as ok had issues with opperators drinks ect dropping onto controllers and connectors on our 350,s so i have checked that , i think it will turn out simple but i am starting to backtrack over things i have already checked. all sensor i see as relevant to starting have been changed as has the fuel pump i have swapped out the rail pressure sensor from a working machine 870, not 670 still wont start, energise the injectors . on my version of MP dr does not seem to allow me to clear any faults unless i am missing something... same as when i see the fault in troubleshhoting, i can highlight that fault but get nothing in the way of information on the fault if i click on details. my version is M Pro 2.12.0.1 so how do i clear the fault record...

further to the above. i have 102.3 636.2 10001.3 157.3 1381.3 on engine controller and 13311.4 on monitor . the think 636.2 refers to some rom issue which made me think of ecm..

sorry guys 636-2 i believe equals P0341 cam sensor and thats been replaced complete with pump unit,however i cant clear the existing codes and anyway it still wont start or give feed to the injectors

670langley said:

hi, thanks checked switch, cutoff ,shows as ok had issues with opperators drinks ect dropping onto controllers and connectors on our 350,s so i have checked that , i think it will turn out simple but i am starting to backtrack over things i have already checked. all sensor i see as relevant to starting have been changed as has the fuel pump i have swapped out the rail pressure sensor from a working machine 870, not 670 still wont start, energise the injectors . on my version of MP dr does not seem to allow me to clear any faults unless i am missing something... same as when i see the fault in troubleshhoting, i can highlight that fault but get nothing in the way of information on the fault if i click on details. my version is M Pro 2.12.0.1 so how do i clear the fault record...

Click to expand...

When you hit troubleshoot and get the list of faults, you hit "retry" several times and any faults remaining are still active.

670langley said:

further to the above. i have 102.3 636.2 10001.3 157.3 1381.3 on engine controller and 13311.4 on monitor . the think 636.2 refers to some rom issue which made me think of ecm..

Click to expand...

The faults above are
102-3 Boost pressure sensor low voltage fault
636-2 G sensor fault( this fault WILL prevent the engine from starting)
10001-3 EGR position sensor fault
157-3 Common rail pressure sensor high voltage
1381-3 I don't recognise this code
13311-4 Fuel level sensor.

670langley said:

sorry guys 636-2 i believe equals P0341 cam sensor and thats been replaced complete with pump unit,however i cant clear the existing codes and anyway it still wont start or give feed to the injectors

Click to expand...

I think you may have an issue with the wiring. The G sensor shares wires with the rail pressure sensor and the EGR position sensor. Try unplugging the EGR motor and also the rail sensor and try and start the engine. The engine will start with most if not all the sensors unplugged with the exception of the G sensor.

on wiring, i believe you may be right , does the shielding around the engine harness play a vital role, much of it has been stripped back previously to get at damaged wiring, there are many joints in the engine harness ,however continuity tests show up as good.
again anyone know how i can get all faults cleared. so i can see whats new.

Are you reading the code through the monitor or by using MPDr? If your using MPDr when you start troubleshooting, once it lists the fault codes, hit the retry button several times. Sometimes it takes up to 20 times before the engine codes clear because on the dash 3 machines the engine codes were quite stubborn to clear. If the don't clear their still active.
If your reading them through the monitor then they will always be active if their visible. To troubleshoot through the monitor follow these steps
Hold the top right button on the monitor whilst turning the ignition on, then let the button go.
press the menu button then scroll up or down till you see service, press enter.
Then you should see troubleshoot, monitor or controller version.
Select troubleshoot and it should start reading the controllers. once finished it will tell you if any codes are present, As said above, if it lists any codes at all these will be current codes so troubleshoot them first.
If you have the 636-2 code then check resistance from the G sensor to the controller.
Have you tried unplugging the items mentioned in my previous post?
The pin numbers to check resistance are as follows
ECU pin 87 – Sensor connector No.3 terminal
ECU pin 98 – Sensor connector No.2 terminal
ECU pin 101 – Sensor connector No.1 terminal

many ,many thanks for that, i will be on that very soon and will reply again . i have sussed out the monitor system , however MP Dr is proving ,as you sugest ,stubborn , i will try again. thanks