Hello, I have this rather interesting foul on my machine. It stalls the engine under load or when traversing and the auto idle is not working, but sometimes all works just fine but only after it has warmed up, until you shut it off, then it goes back to staling. it overheats because of it, it never overheated before. I have extensively researched why it might be doing it and have tried countless things to no avail. Even the official Cat mechanic was here and could not find the issue. I am turning my head here to some wise people who might know what's up. List of things done ( maybe done them badly? ) Engine and fuel: The engine has a new turbo I was testing if it had enough fuel, tried it run on a fuel jug, still the same The engine is not smoking any colour. checked all the fluids cat changed filters and all this stuff adjusted the valves fuel pump and injectors will be serviced but that is not why it stalls... engine starts at -10c without any problems Cat adjusted cable slag on the throttle but I don't think they did a calibration, might be it? how to do it? (The machine responds normally to the speed settings and even throttles down when you press a button on the joystick) Hydraulics: Hydraulics filtres have been changed The pilot black ball thing has been changed (I don't know what it is called) cat has adjusted the pilot pressure cat tested solenoids on the distributor the pump is reacting to the display settings pressures on the pump and distributor look good, even factory spec when checked (cat said it's impressive it has such good pressures on this old machine) I don't remember it all, will add if I remember. All of the above has been done because of this issue not before I am out of ideas, maybe an engine speed sensor? they said it was okay, but I don't think so. Bad controller? bad wiring? sticky solenoid? why it sometimes comes back to life like nothing is wrong. I don't know. Machine VIN: 4MM00566 ALL HELP IS MORE THEN APPRECIATED Great regards peter
The main pumps horsepower control can be influenced by the mode setting you operate in and the reading the the controller receives from the rpm sensor. Typically if the rpm sensor or pump regulation is an issue, the machine will stall the engine when rolling and deadheading the bucket function at just above engine idle. The cam and cradle assemblies in the main Kawasaki pump maybe starting to bind and stick. Pressures can still appear ok but the pumps flow rate is too high. If the rpm sensor and the main pumps PSV solenoid is working correctly then I would recommend removing the pump and doing an inspection. The black ball thing is called an accumulator. it stores hydraulic fluid under pressure against a nitrogen gas pre-charge that is separated by a diaphragm.
Thank you for the info. But when it works it works until you shut it off, that would suggest its a controller, rpm sensor or PSV? Not the pump? But on the pump regulation note it only “fixes” itself when it warms up which would suggest something unsticks PSV then? How do I test it? What voltage should it be? Or what's the procedure Thanks
Sorry as I don't have access to the CAT SIS system so I cant get you the info your require but someone here may be able to help. Their was usually a PSV calibration and sweep test you could do via the monitor for checking the PSV pressure output and the pump would have a dedicated test point for this pressure signal ( usually in the center of the pump at the top) You would input an access code into the monitor to bring up the service menu and then set up the PSV calibration and sweep test. The controller would then ramp the solenoid up to its max value and back down and you could see this on the pressure test gauge. You could then set the psv at a fixed point and check that the pressure gauge had the correct pressure reading from the solenoid. The PSV solenoid might also have a set screw, so when this is wound all the way in, the solenoid is mechanically overridden and gives a fixed output pressure to the pump unit which reduces the pumps horsepower setting. I think the solenoid might be PWM controlled, but im not 100% sure? For the Auto idle function their are usually 2 pressure switches mounted on the main control valve that detect when you use travel or an upper implement, it then sends a signal to activate the auto engine control function
I would like to assist you on the Auto mode on Cat . If there is no code, May you check the Pick up speed sensor on the flywheel. Its magnetism or reset it. This sensor enables auto raves on Cat exc. On wheel loaders also it enables gear auto shift. Try that.
See the attached which may help. It is the SysOp and T&A procedure for the engine/pump control system. Also FYI to the OP. Your 317 is an A model, not a B. It was built in June 1996, 2 years before the B models were introduced.