I have a 96 Komatsu Pc200-6 that had a dead cylinder when I purchased it. I rebuilt the engine last winter and ran it some clearing trees. The hydraulics are slow compared to other machines I've ran. The engine will not pull down or smoke. It just doesn't seem to be working very hard. Recently I have been reading on here about different hydraulic problems with machines similar to mine and came across the prolix sp? switch. If I flip the bypass switch where the fuses are located I seem to have all kinds of power and speed. It will also now kill the engine if you work the hydraulics enough. I don't know what flipping the prolix switch actually does electrically but the machine functions much more like I think it should when flipped. Any ideas on what I should look at? Thanks.
In normal operation the computer sense the speed of the engine and then applies a voltage to a solenoid on the pump that will change the output of the pump to keep the engine operating only to its design horsepower. What the Prolux switch does is when the computer isn't working properly it sends a set voltage to the solenoid which is about three quarters of the engine design horse power. It sounds like the switch was already in the bypass position and when you shift it the control goes back to the computer which is overloading the engine. There are a lot of things that could be wrong. Do you know how to get into the monitor panel to check for any codes? Here is a video that shows how to get in. Let us know what you find.
Okay. I had a chance to check out the excavator again. I have attached a picture of the when machine will bog down to the point of killing the engine. I'm pretty certain it acts this way while in bypass mode. I have a list of codes that I pulled from the monitor. 101 44 102 44 E2:22 44 2:33 4 2:37 4 2:13 2 Thanks
101 and 102 just mean the battery was disconnected at some time. They will disappear when you clear them. The E222 is a fault code which is Short circuit in LS control EPC solenoid system. 233 is also a problem, disconnection in front pump TVC solenoid system. It is the solenoid on the front pump. I would suggest checking the wiring and connector to that solenoid for problems. 237 is the same issue on the back pump. disconnection in rear pump TVC solenoid system. Both being disconnected means the computer doesn't know they are there which to me means the engine should be overloading all the time no matter which way the switch is thrown. 213 is disconnection in the swing brake solenoid which would make it so the swing would be locked up. When the swing brake is on the hydraulic system is in two stage relief which means the output of the pump is raised and so is the relief valve pressure. The swing parking brake on puts the machine in maximum output but you can operate the swing. It is looking to me like you have wiring harness issues. At this point you will need a service manual as you will need to test the solenoids and other electrical components then work your way through the harnesses.