I have a 892 ELC that had a issue with idling down while operating it. As if you let go of the controls so it idles down. And it has slow functions. Plenty of power and the tracks work great. Just the upper structure that is affected.
Just so I am clear, you say the engine rpm drops to idle while operating it? Before it drops does it work OK?
How is it if you turn off auto idle?
Sounds like a bad pilot pressure switch.Check behind the cab under the panel where the air cleaner sits. I believe that they are interchangeable.
Is your 892E the early model (not pilot controlled), or the later one with pilot controls. May change the troubleshooting steps.
It is the last model 892 made. It has the 330 john deere hydraulic system. Also today I got mad and unhooked all the sensors on the hydraulic system. It made no diferance. I unhooked a few at a time tell there were no more to unhook. I have changed the pump valve controller. Both pressure switches. All the fuses. All the filters. Oh and the main pumps 250 hrs ago. The engine never works like it never builds turbo pressure never lugs down in any way. Drops 12.0 rpm at stall pressure. The tracks work great very strong very responsive. Pressures are spot on with a gauge and with the john deere service computer. The only thing that does not work is the heavy lift button on the controls it does not chage pressures when pushed. The mode button in cab slows the engine but has no affect on the hydraulics. It is as if it is stuck in the fine control mode. The voltage at the flow control selinode is 10.4-13.6 so it is getting half the volts to be full stroke to the pumps. So I hooked a jumper wire to the selinode put 24 straight to it while it was un hooked to not back charge the computer. Nothing no diferance. Thank you for any and all help i am at a loss and my dealer just keeps guessing at it. I have bought 2 PVC and paid then 3500 I could a put the 3500 in parts. Any ideas I will try it.
Yes it works fine but it is very slow on the upper structure. As if it is stuck in fine control mode. Auto idle off it does not idle down on it's own.
Please post a serial number. Does the machine mistrack? So the engine rpm remains at fast idle but the upperstructure (boom, arm, bucket and swing) are slow? You say the tracks are strong so humor me, perform a cycle time test on the tracks. Warm the oil, raise the track, Power mode on "P", Work mode "M" on General Purpose 1, Track speed set to rabbit, measure the time it takes to complete 3 revolutions from a running start. Post results. Why were the main pumps replaced?
It sounds like this was a guess to me.
That sounds like a good place to start.It might also help to set the high idle to 2225 rpm and check the pulldowns on each pump.Warm up the hydraulic oil and pin both tracks.Each side should pull down approx 60rpm and both together 125 rpm.Also check and see what happens when you travel and use a dig function at the same time.If the dig function speeds up the the flow combiner valve is working as it should.
This was a auction machine I bought from the city of Kenmore. I am not sure why they were replaced just that JD replaced them and marked the hours on the pump tag.
While tracking in p mode middle speed. Boom goes up very very slow, arm very slow swing works ok and bucket works but I think a little slower than normal. Forward or reverse
Also now when digging it will idle down on it's own if I do not use the bucket out or swing function in a timely matter. It will only speed back if I use bucket out or swing. Or speed it up manually or dont use the auto idle. It seems as if it is not registering I am using the boom arm functions.
What were they guessing about????
Auto idle it stays running fine but it is slow digging functions like it is stuck in fine control mode. And the mode switch does not change anything but the engine rpm functions do not change or very little change.
Serial number is FF892EX012321. Thank you all for your help. I am at a loss. If any of you are looking for a project and think you can help fix it I would rather pay you then the dealer that has rapped me and sold me part after part after part that has done nothing but cost me major dollars. New PVC new engine controller new main pressure sensors and a huge diagnostic bill. I am to the point Im.starting on one side of the machine and replacing every sensor or thing that has a wire going to it. Tell it either fixes it or I get them all changed. Then i guess I will start on the pilot system taking apart ever valve every line. This machine is like new perfect condition been in a sand shed its hole life. Has 10134 hours on it but had only worked for about 2500. It spent many hours idling between truck loads. Some days 8 hrs and load two dump trucks.if that matters to our current problem. Pumps were changed because john deere recommended it at 10000 hours no problems at that time that he can remember. This machine still has paint on the tracks and track frame it has never worked a minute in its life. It has loaded around 65000 dump trucks with sand. That's the history on the machine. JD the dealer from where it was purchased did all the maintenance on the machine. What ever that was I do not know. but the city Forman told me the dealer did all the oil changes and fixing. They only greased and cleaned the windows.
I assume all the fuses are good? Please follow instructions in post #8 and post #11 (if you have access to a diesel digital tachometer). To solve this issue will require some extensive electrical/hydraulic/mechanical knowledge as well as some testing equipment (tach as mentioned, pressure gauges, etc). Those are simple things to check with minimal expenditure.
You may want to buy the diagnostic service manual from Deere. The help on this site is great/excellent, and the book helped me understand more on how the 892 works (as mine had some weird issues when I got it).
I have a tach gun. The engine pull down is 6 rpm. I have every book for the machine. I have full flow flow meters. Pressure testing equipment. But need help with what is normal and what is abnormal readings. And where things are. Yes the book has a item location diagram. Yes I can read yes I am still confused on what is what. I have not had the machine to the shop since the issue's have come about. Thought the dealer would be able to fix it out here on the job sight.
Was the pulldown performed by stalling the tracks one at a time? If not do it that way and post results (specific rpm please).
OK hawk281 sounds like you are getting a little frustrated, been there done that.Have a coffee, beer,toke,what ever works.And don't start hooking up 24 volts to solenoids or you will just cause more problems!It sounds like the pumps are not getting a signal to stroke by using the dig functions.I have sent you some my old shop school diagrams and pressure settings. Try sticking a gauge into the sense line on the pumps and see what you get.If your pressures and pulldowns are good for the propel side then your pumps are working like they should.The problem may be a bad solenoid or a check valve.Also check the flow combiner valve as I recall we did have to reseal some of those and there was a Service News Letter about them from Deere.That valve shuttles the pumps when you are using dig and propel at the same time (one pump supplys the dig functions and the other pump supplys the propel)Have patience my son.Read the theory of operation on the hydraulic system.If nothing else Deere wrote a good manual.
Thank you for your help!!!. I have tried to diagnose this problem for couple weeks now. And the dealer here keeps wanting to sell me major parts that I know is not the problem. Now they want me to buy a new main spool valve 17000 dollars. This is after the second pump controller and one engine controller. The bucket dump function is the slowest out of all the cycle time tests. Then dipper in, then boom up. Then bucket curl in. I just finished this job here today. I will be moving equipment home starting tomorrow. Once I get the 892 to my shop I will be able to perform all the tests and procedures you recommend. I am now working out of my service trk 2.5 hrs from my shop. Thank you for your advice and direction.