Hello folks, I have a 2005 CX 240 that with any function kills the engine even at full throttle. Not a fuel issue as it has 14psi fuel pressure to stall. It’s like a load valve is stuck closed or something not letting the pump or pumps destroke. Has anyone delt with this before I start replacing parts? Thanks in advance.
14 psi or 14,000 psi when it stalls? Does it stall if you slowly go into a function?
14000psi? 14psi fuel pressure when engine stalls so it is not releasing hydraulic pressure some how. You can slowly load engine until hard stalls. Throttle response is instant from idle to max governed rpm.
Fuel pressure from the injection pump to injectors should be several thousand PSI. The hydraulic pumps/valves have reliefs on them to prevent over pressure, and each valve section has a sectional relief for each tool function. It sounds like the engine isn't able to produce the HP to run the hydraulics in general ie.. fuel pressure/flow.
The information I was getting was the fuel gauge in the cab was the same it has always been when engine dies. I installed the gauge to keep tabs on the electric lift pump to keep the VP44 injection pump alive. I will know more today. Thanks for your thoughts so far.
So after pulling codes the only code shown is in screen 5 of diagnostics which of course M, M 0080 which is a pilot pressure switch. What is interesting is I can clear the code and it will not reset in the E screens 1-4 but immediately show back up in screen 5. And yes, the fuel pressure is good at 13-14 psi all the way to the injector pump. But you can feather any hydraulic function and it will operate but when you apply enough pressure and P1 or P2 hits 3600psi it will stall the engine. Engine starts and runs perfectly as it always has. Instantly goes to full throttle when H is selected without hesitation. It’s as if the ecm is defueling the VP44 pump when pressure climbs. Regular pressure is supposed to be 4350psi and the 8 second full stroke pressure is supposed to be 5400psi from what I am reading in the tech manual. I pulled the connector lead for that sensor for code 0080 and no new code showed. I even jumped the connector lead to test the switch and no change, still threw the same code.
When P1 and P2 go to 3600PSI, is that with a function at the end of its stroke and pressuring out or while the implement is in movement? If you have Cummins Insite or access to it, you would be able to monitor the Injection side fuel pressure to see if it is falling off when it stalls. Also does it smoke when it stalls (what color smoke if it does) , and does it instantly die or lug like its trying to stay on and die?
It will stall out during any quick movement of a joystick prior to a cylinder bottoming out, and the pressure is 3600psi at stall. If you let off before stall engine recovers fairly quickly. Runs smoothly at wide open throttle in H range. Have no access to advanced diagnostics and dealerships refuse to diagnose, only replace parts such as injector pumps, a host of sensors, out of desperate compensation for their lack of diagnostic ability or aptitude to use the diagnostic tools provided to them. Already paid them $900 for a 3 hour service call where they told me to replace every sensor on the machine and if that didn’t fix it replace the injector pump. And they left the field with the machine exactly as it was when they arrived.
But the M0080 is still popping back up immediately after clearing. Will this derate the engine?
Pilot pressure I believe is in reference to the hydraulic pilot oil pressure, The joysticks use pilot oil to control the valves for the cylinders. So that code shouldn't be causing the engine to stall and if the controls are working the sensor could have a bad plug or wire. Does it stall if you try to tram it as well? Also did the unit just start having this issue, or has it progressed to this?
Unsure what tram means, but travel both forward and back is the same as all other hydraulic loading operations. Machine worked fine all day. Next morning after the warm up cycle this happened. Changed both fuel filters but again no fuel pressure drop at filter just before injector pump all the way to stall.
Sounds to me more like a hydraulic problem than a fuel problem. Sounds like hydraulic pumps are going straight to max flow. Could be a pump solenoid/sensor in trouble.the code you have for pilot pressure switch do you know which pressure switch it is. If you have a pilot sensor reading faulty it could be sending the pumps to full stroke which will pull down the engine
That’s what I have been thinking from the beginning. But have no idea how to find that problem. The factory Case manual is useless for troubleshooting.
Where is the sensor you disconnected located maybe post a picture of it and someone might be able to point you in the right direction. Any other sensor on the machine the same that you could swap it with to see if fault changes
It is located it the pilot control bank behind the cab. What is interesting is disconnecting it did not throw a new code and did not change the operation of the machine.
It's a low pressure sensor for your pilot controls. Can you swap it with another one and see if the fault code changes.
The best way to sort out if it is engine or hydraulics I would suggest is going to be with a flow meter, loading valve, and pressure gauges. Tie in on the hoses off the valve bank for one of the large cylinder functions. Then you can see what the pump is doing, and load it down incrementally with the loading valve to see if the pump controls and reliefs in the valve are working properly and how the engine responds to the load.
Thanks for your reply. I think I know where this pressure switch is located, but in testing by unplugging the device, no new codes were thrown and nothing changed with the problem. Does anyone know if this code will derate the engine and why it instantly goes to the 5th screen in diagnostics which is history instead of the first screen which is for active codes.
It is $250-$300. I wished there were some way to test it before I purchased a new one, and if I knew this failed switch would derate the engine like what is happening.
Thanks again for your help. I can’t tell from the picture but do you have that part number?
Part no. KHR10790 If you go on fleabay etc you will find them cheaper. There are two of those sensors on your machine one for the upper functions and one for travel. The fault code is saying either one could be gone or it could also be wiring.
Hello. But isnt that the pump has only one solenoid on the botom of the pump? It is old model for electronicaly controled regulators for the pump. Have you checket the servo pressure on the machine, cous i thik that this pressure switch is only the indication for the loss of servo pressure.
Thanks for your replies. So I replaced both sensors for the uppers functions and travel. That cleared the code but the stall condition still exists. When any function is activated, (travel, anything, if you go hard it will stall engine at 3600-3700 psi for both P1 and P2 pumps. Definitely not fuel related as mentioned multiple times fuel pressure at the VP44 pump is 13-14psi and the throttle is instant when you let off control before engine stalls. So now no codes in diagnostics, all filters on machine have been changed. Desperate for any help.
At first you should check main relief valve cous reliefe pressure is 4980 psi (Im used to metric, at first thoug that the pressure is ok). Check that the orfice is not cloged, and the neadle is not worned out. Cous pump starts to reduce flow when it reches aprox. 4600 psi if it cant reach it the flow is not reduced. Aded a picture of the valve. Second is taht the horsepower controle isnt working properly. On the bottom of the pump you should have a solenoid ( aded picture below). Next to the solenid there is 1/4'' check point. 0 bar max flow, +-39 bar (servo pressure) min flow if you disconnect the solenoid there should be 39 bar if the sonenoid works properly. It will show error, but you can run it like that just tu check if it is still stalling.
Thanks Reinis. But I thought there were 2 separate main relief valves, one for each pump. Both pumps are stalling out at roughly the same psi when a circuit for each pump is loaded to engine stall. Leaning more towards injector pump although the dozen or so VP 44 pumps I have had experience with in the past simply died and would not even start the engine when they failed.
I might be wrong but usualy there is one relief valve for boath pumps.
I don't know how these pumps are regulated off top of my head but I've ran into a few older machines that regulators where frozen internally some i disassembled cleaned resealed some changed regulators some just changed pumps. I'd imagine that uses computer electronics to control a pwm solenoid that controls pilot pressure to pumps but could also have solenoids in pump regulators. You need to study system determine external pump regulation is changing then go after pump regulators them selfs. Computer is going to need to see rpms and pressures to regulate can u verify they are working on screen
(Second is taht the horsepower controle isnt working properly. On the bottom of the pump you should have a solenoid ( aded picture below). Next to the solenid there is 1/4'' check point. 0 bar max flow, +-39 bar (servo pressure) min flow if you disconnect the solenoid there should be 39 bar if the sonenoid works properly. It will show error, but you can run it like that just tu check if it is still stalling.) I disconnected this sensor and made no change. But I think you are on the right track as the diagnostics in Chk 2 shows the engine stops at exactly 50% rated power, as if the ecm is definite derating the power. When you unload from any control the engine instantly climbs back to governed rpm of approximately 2000rpm. Once again the engine will stall at 3600 psi from both P1 and P2 pumps when the corresponding circuits are activated. I am now positive this is not a fuel issue, 14psi at injector pump when engine stalls. I am also fairly certain it is not hydraulic stall now as both P1 and P2 pressure sensors show engine stall at 3600 psi and the high pressure setting is supposed to be at 5400psi. I am desperate now for any additional help.
I had a very similar issue on a lbx lx240.check your engine condition, fueling, and pump regulator adjustments which will affect engine load on each pump
I have 240 also doing the same thing put inj pump &new hyd pump didnot change