hyundai problem CUMMINS LOOSING POWER

[rustylhurtt]

I just got in the excavator business . I had a cat 321lcr rented for this fema job but now i have bought one . I bought a hyundai 180 lc 3 robex when it got here . You get in a hard dig or try to track up a steep hill it kills the engine . I believe it s a valve in the pump stuck . The cummins just pulls down and the dies . The motor is not missing and does not blow black smoke when it pulls down. Some one told me the relief valve is stuck doed any one know where the valve is located the guy i bought the machine from (400 miled away) said it was not doing this but it has set for 5 months so can any one help

 

[SterlingR]

Typically if the hydraulics are dragging it down it would blow black smoke. It sounds like fuel filters to me . Try the simple things first.

 

[dayexco]

have you, or the prior owners run it out of fuel a few times? we fried an injector pump on our cx210 case doing that. mechanic said that was the achille's heel of the cummins engines....running them out of fuel takes all lubrication of moving parts in injector pump, and doesn't take much to fry them.

 

[willie59]

Kinda hard to say since we're not there to see/hear it. I agree with looking at fuel first. When your tracking up a hill, as you describe, and it pulls down; when the engine is near stall and you quickly let go of the drive levers, does the engine rev up quickly or very slowly? If slowly, I'd say you have a fuel delivery problem. If the engine revs quickly, then you go to drive again just to stall all over again, you could have a hyd pump that's doing an overstroke delivering more hyd oil than is needed by the system.

 

[John C.]

I'm not saying this is your problem but I have experienced this on several machines that have Cummins engines. There is usually an in line "strainer" between the fuel tank and the transfer pump on the engine. It looks exactly like the inline fuel filters that used to be used in cars.

I have seen those strainers taken out and replaced with the filters from the local auto parts house.

The issue is that the strainer has a brass screen on the inside and is cleanable. It is there to catch the big pieces of junk that get in the tank. You simply take it out and blow air backwards through it, flush a little fuel or solvent in it and blow again till dry. The auto parts filters have paper inside and plug up pretty quickly either when water hits the paper of sludge gets in there. They are not cleanable at all. I would pull it out and look for part numbers or brand printing. You can get the proper strainer anywhere they sell parts for Cummins engines.

I have also seen the problem that ATCOEQUIP describes. At this point I hope the fuel system is the problem.

Good Luck!

 

[rustylhurtt]

i canged the water seperator and fuel filter today and the machine is no better i also changed the hyd. filter no luck the either but the fuel filters were very dirty and alot of black crud ran out of them when turned up side down also when u let of the levers the engine revs up very fast i also noticed one track turns a little faster than the other could that have anything to do with it thanks for all your input

 

[terex]

Im not saying this is your problem but I would agree with John C above that manafacturers often put 'in line' strainers between the fuel tank and the fuel filters, these strainers are often very small and can be hidden in fuel pipe unions or in the fuel tank itself. Try looking for one of these before ripping the pump to bits!

 

[willie59]

i canged the water seperator and fuel filter today and the machine is no better i also changed the hyd. filter no luck the either but the fuel filters were very dirty and alot of black crud ran out of them when turned up side down also when u let of the levers the engine revs up very fast i also noticed one track turns a little faster than the other could that have anything to do with it thanks for all your input

If the engine revs back up quickly after the engine stall, doesn't sound like fuel is the problem. Although, you do have a fuel problem with all the crud. Your tank should have a drain tap on the bottom of it, you need to drain off the water and dregs at the bottom of the tank, do it frequently until fuel is clean. Can't offer an opinion yet about your hyd problem, I'm not familiar with the machine and it's components.

 

[Iron Horse]

It would not be a relief valve problem . There would be no need for the valve to go into relief mode whilst tracking . It would only need to do this if you were stalling the tracks completely . How steep are the hills you are tracking up ?

Have you done ANYTHING to the machine since getting it ? Have you had a hydraulic quick hitch fitted ? Have you put hammer/auger pipes on it ? It sounds like the pump is dead heading for some reason .

 

[rustylhurtt]

the machine pulls down when going up the ramps on my lowboy i also noticed the machine wont choke itself if your tracking foward and moving the boom or the bucket but if you stick the boom straight out and raise it fast it kills the engine thanks for all the sugestions also the machine does not have aux. hydrallics ive never turned a wrench on this machine just changed the filters also im having a little trouble getting the air out of the line after changing the fuel filters

 

[willie59]

It would not be a relief valve problem . There would be no need for the valve to go into relief mode whilst tracking . It would only need to do this if you were stalling the tracks completely . How steep are the hills you are tracking up ?

Have you done ANYTHING to the machine since getting it ? Have you had a hydraulic quick hitch fitted ? Have you put hammer/auger pipes on it ? It sounds like the pump is dead heading for some reason .

I agree. Even if the main relief valve was stuck, the circuit reliefs should still work. The chances of multiple relief valves being stuck is...that's just too wierd! I'm still trying to determine if it's an engine or hyd problem. Let's review what we have so far; 1) while tracking steep hill or hard digging, engine stalls. 2) no significant black smoke while stalling under load, may not mean anything but still worth noting. 3) fuel filters changed, no change. And 4) engine revs up quickly after load (levers) is released. I still think one track faster than the other is a seperate issue at this point, but I could be wrong. One thing I have to ask here; it's a Cummins engine, does it have a wastegate valve on the turbo that has a hose/tubing line that goes to a fitting on the injection pump?

 

[rustylhurtt]

I agree. Even if the main relief valve was stuck, the circuit reliefs should still work. The chances of multiple relief valves being stuck is...that's just too wierd! I'm still trying to determine if it's an engine or hyd problem. Let's review what we have so far; 1) while tracking steep hill or hard digging, engine stalls. 2) no significant black smoke while stalling under load, may not mean anything but still worth noting. 3) fuel filters changed, no change. And 4) engine revs up quickly after load (levers) is released. I still think one track faster than the other is a seperate issue at this point, but I could be wrong. One thing I have to ask here; it's a Cummins engine, does it have a wastegate valve on the turbo that has a hose/tubing line that goes to a fitting on the injection pump?

im not sure i will look in the morning and follow up

 

[Iron Horse]

An excavator will display the symptoms you describe if it is in the high range position . High range is for light digging and fast tracking . If it is in high range it could stall going up the lowboy ramps and could stall in tough digging . Being new to this machine you may need to find the two speed control . It will either be a lever on the left consul or a Rabbit/Turtle switch on the dash .

 

[rustylhurtt]

An excavator will display the symptoms you describe if it is in the high range position . High range is for light digging and fast tracking . If it is in high range it could stall going up the lowboy ramps and could stall in tough digging . Being new to this machine you may need to find the two speed control . It will either be a lever on the left consul or a Rabbit/Turtle switch on the dash .

thanks the machine tracks slow but the high low selector will not light up it tracks slower than the cat i had rented in low

 

[Iron Horse]

When tracking , do you feel the machine pick up speed and slow down again when the switch is activated both ways ? I'd be having a good look in that area , the light not illuminating could be a tell tale of the problem .

 

[rustylhurtt]

When tracking , do you feel the machine pick up speed and slow down again when the switch is activated both ways ? I'd be having a good look in that area , the light not illuminating could be a tell tale of the problem .

no the machine only runs one speed (very slow) the switch is on a screen with a with two lights (slow and fast) and a selector button but nothing is lit up thanks for all the sugestions

 

[Iron Horse]

My machine has the same mechanical components as a Hyundai . Mine also has a Rabbit/Tortoise symbol and a switch in the dash . On mine , these are NOT hooked up even though they will illuminate . The two speed on mine is a lever on the left consul . Yours could be the same .

 

[firetruck dvr.]

Hello rusty. I notice you are from Salem Ar. I am at Little Rock and just recieved A new 160lc from Equipment Resource Management in Maumelle. They are a top notch dealer and have a great mechanic. I have not had any issues with my machine, but I had a lenghty conversation with the mechanic before delivery of the machine. You might give them a call and see if they can come out?

 

[John C.]

Now what you are describing sounds more like a pump and control problem. Basically somwhere there should be a speed sensor that will tell a controller the engine speed is dropping. The controller would actuate a solenoid on the pump to change a pilot oil pressure to cause the pump to destroke and relieve some of the flow of the pump and reduce the horsepower demand on the engine.

Your problem can be electrical concerning possibly a solenoid, wiring in the form of shorts or breaks or the controller itself. The problem can also be hydraulic with plugged passages or stuck control spools. Finally your pump could be mechanically broken inside.

All this is the reason I stated you should hope the problem is in the fuel supply to the engine.

Judging from your posts I am going to assume you have limited knowledge of the systems on this machine and recommend that you contact a dealer for service. That brand of machine is not real common in this country, is usually not well supported, provides little technical information to customers and only parses out that knowledge to their own support personnel as things happen. You may be lucky though in that most of the component parts such as pumps and electrical components may be used on other manufacturer's machines.

Good Luck!

 

[willie59]

Pump and/or control problem is my inclination as well, but it's too hard to tell without being there hearing/seeing the machine. As John C described, it gets way more complex when you have to troubleshoot pump/control problems on a forum because excavators have very complex systems. That's what allows you to have a machine that can be slinging bucket loads of dirt into a truck very rapidly then in a moment change to a machine that can gently scoop the Robin's nest off the ground that you just bumped out of that tree with your counterweight. I just have that one more question about the engine I would like to eliminate. I don't know which Cummins engine the machine has, but some Cummins engines use a turbo wastegate valve that is controlled by turbo boost pressure. The line that sends pressure to the wastegate is also connected to the injection pump and controls fuel to the engine. When the waste gate valve craps out and leaks boost pressure, the loss of pressure affects fuel to the engine as well, then the engine runs fine but is gutless as far as power.