Hello everyone. I'm hoping some of the expertise on this forum can help me. I am having issues with my kobelco sk210 lc-8 POURING black smoke when it's under load. Only under load. I can rev it high and it's fine, but as soon as I lift the boom or perform any function with the controls it pours black smoke. Here's what we have done so far to troubleshoot: A little history: We had it at a friends house and it was running fine. We had a blizzard with about 2 foot of snow. Long story short, after the snow melted, we went to move it. about 20 feet and it died. After a fuel pump replacement and filters, we came to find out the entire Lower fuel filter housing was completely packed full of mud. So after all that was cleaned up it was running great...probably put 50 more hours on it....Then we moved it to a new job and noticed it was slowly losing power and more black smoke, so we stopped running it. Replaced the filters again and then took the fuel tank off and scraped a significant amount of smelly mud and random parts that didn't belong in the tank. Didn't help. First thing that came to our minds was not enough air and too much fuel..... * First we checked for dirty air filters. Ran the machine without them for a quick test. Not the problem. However from sitting a mouse had built a nest in there... and to my luck when I had my head down in the engine, ol jake the snake decided to come out. I about did a back flip off the counter weight lol. * We disconnected innercooler lines, etc.. to make sure no restriction was in the lines. * Rebuilt the turbo. Noticed a little oil leaking past the seals, and turbine had too much play for our liking. So nice rebuilt turbo. * Took the little heater off on top of the engine and that was fine. * cracked each injector line to see if they affected the engine. All injectors seemed to perform as they should. * Blew out all of the fuel lines after disconnecting all of them. The only thing left that we can think of is the injection pump, so we took that off, then we called B&D diesel and they said to put it back on and it didn't sound like the pump. It sounded like loss of fuel????????? And try to bypass all of the lines by hooking up a jug of diesel fuel and a line straight to the injection pump.... Thunderstorms limited our work yesterday so were going to try that this week. The engine is a CNH or IVECO... There is a CNH tab right on top of the motor.. Anyone have any ideas? And no we havn't purchased a service manual yet..... it's coming though.:Banghead
Update: we bypassed the fuel and hooked a jug of diesel to the injection pump. Same problem. Also it happens at idle and at full rpms but only when you activate the hydraulics fully. If you lift the boom gradually it doesn't do it as much. Any thoughts?
Fuel being that contaminated sounds really bad, but I would think it would skip, white smoke, or misfire if that was the problem. You took care of the intake side of things, how about the exhaust?
Yeah. It was pretty bad. But the good thing is the filtration on that machine. The bottom larger filter goes straight up to the fuel pump and then from the fuel pump back down to the second and third filter, then back to the injection pump. The smaller filters didn't have anything in them or the housings. So it looks like the large filter took one for the team. Yesterday we replaced the smaller filters just to weed that out. Exhaust: We took the muffler off. We separated it from the turbo where that silver band clamp disconnects. Turbines spin freely. It's odd. You can turn the throttle up and leave it there. Engine doesn't miss a beat. As soon as you pull back on the lever to raise the boom, black smoke fills the air and the rpm's drop down. If you pull back gradually though, it's not as bad. Another thing that I don't quite understand is it does it at idle(under load) and at full throttle (under load). My assumption was it would be able to deliver enough fuel at idle under load more so than full throttle. So the only thing I can think it would be is the injection pump or the injectors.... We also checked the air flow from the intake yesterday again. It puts out more air than my leaf blower!
Thanks for your response btw! I was wondering if anyone was still on here lol
Not enough air and too much fuel isn't as common as you'd think on a diesel, they run with such an excess of air usually. For the injection pump to be causing this the timing would have to have advanced a lot (unlikely?). The injectors could be leaking, you wouldn't think they'd all fail identically though? All that leaves is that there is more load on the engine than there should be, how's the hydraulic system look? And does it act the same way hot and cold?
Yeah I'm grasping for straws on this one. I wouldn't think the injectors would be bad. I would think there would be a miss or something, but maybe not. We haven't looked at anything yet on the hydraulic system. I think we will have to find a book before we start exploring that too much. I am under the same thinking though..... maybe some kind of hydraulic circuit or something.. Also no codes on the display except for incorrect hours on meter.... or something like that.. It performs the same way hot or cold btw
Well, pulled the no. 1 injector out. Fairly dirty. Were just going to pull the rest and clean them and take some bore brushes and clean the cylinders.. If that doesn't fix the issue, the injection pump is the next step.
If you're taking the injectors out, have them pop tested by an injection pump shop. Cleaning them won't do much, if anything. Same for the cylinders, cleaning just doesn't matter. Have you sent in a hydraulic oil sample? or checked the filter for debris? it would stink to rebuild the injection pump and then find out the machine is junk because the hydraulic system is messed up. Some other things to test under load, boost pressure, fuel pressure going into injection pump, exhaust back pressure...
10-4. Thanks Delmer. The injection shop told us to bring him the injectors and the pump, so yeah I'm assuming they are going to test them, but we were going to clean them and put them back to test, but if cleaning them doesn't really matter then, we can just take them up to the shop to have them pop tested. Wish I had the equipment to test them myself, but oh well. I'm kind of new with the hydraulics. How does the hydraulics affect the engine blowing smoke? I've rebuilt cylinders and valve bodies, but never had to delve into hydraulic circuits and such and how it affects the engine.... We have not sent a sample anywhere yet or checked the filters. We were thinking strictly an engine issue...
I'd bring the injectors in first, a lot easier and it doesn't look like you're in a remote location. This is an odd problem, even so, I'm surprised at the lack of responses? A diesel lugging down and blowing black smoke just doesn't make too much sense. If the fuel is there then it should be making the power, UNLESS the fuel is too early because the timing is advanced (I don't know if that's even possible to fail that way?) or because the injectors are leaking under load. I don't know what kind of injection system this is, inline pump? common rail? The trouble you had with junk in the fuel makes you think it's fuel related, but it was 50 hours ago and you had two more filters in line to catch the original junk. The hydraulic system malfunctioning is kind of a last resort, "what else could it possibly be" idea. If a pump isn't being controlled right, or possibly is leaking?, then it could use more power than it's designed to and cause the engine to lug and blow smoke. Another thing to check is the intercooler and lines for leaks, that could cause black smoke and low power. HeavyEquipmentForums This thread is one way hydraulics can stall the engine, his pump isn't turning off when the cylinder hits the end, and stalling the engine. Different than yours but you get the idea.
Hey Delmer, We pulled all the injectors yesterday. Took an old fuel rail and cut one of the fittings off, welded it to a slide hammer adapter and made a nice little tool to pull the rest of the injectors. They were dirty, but the spray pattern was correct on them. Were still going to take them to get pop tested. Runnin out of ideas buddy.. Last but not least... the injection pump. We were thinking about running an electric fuel pump to the inlet on the injection pump, but it's hard to rig a line up with the inlet being so big. We broke one of those fuel fittings with the retainer rings off. So now we have to track one of those down. As for the hydraulics, I would assume(ass-u-me) that being computerized, solenoids, etc... ECM would throw a code or something....The engine being mostly all mechanical I can understand why It would not. I don't know if these would be legit tests or not but we were thinking: 1) we could pressure test the pump somehow 2) hook up a boost gague 3) take the injectors and pump to get tested..... 4) Lastly, light a match, and throw into tank.. P.S. I can't believe the lack of responses either. I thought maybe I was just PM'ing you back and forth and nobody else could see them lol! Oh almost forgot... This is a common rail system. Very easy to pull apart the injectors and clean them.. The injection pump is a bosch.
Only thing I know for sure is that you and I are over our heads... You would think that a computer would throw a code in a situation like this, but if the right/wrong? sensor is acting up the computer won't know the difference. I've never heard of a mechanical common rail engine, out of my league I will guess that the common rail system adds a few more possible explanations to the engine doing this without hydraulic malfunction.
Serial number? The early ones had Hino, later Tier 3 EPA units look like Cummins but definitely not common rail.
Does the problem go away when you change computer modes. Heavy, STD, light, etc
I had the same problem on my sk350 -8. It was the turbo.
You've removed air filters, checked piping, new turbo. Sounds like it's not air. I would stop messing with the fuel system, black smoke is lack of air, excess fuel, improper timing, or overload. If you haven't checked the piping between air filter and turbo, you need to do that. Also, between air filter and outside air. If that all checks out good, and you're certain you have pump timing correct, only thing left is the hydraulics. I don't know Kobelco, but I'd be willing to bet there is some sort of pump control failed, or a bypass valve that is malfunctioning to overload the engine.
Just a thought but there isn't an aspirator box on the intake piping before the filter. Mine was plugged with mud and debris from power washing and then being run before it had time to dry out and bridged over with mud. For what it's worth, John
Hey CD, Yeah that was actually the second thing we checked. First we took out the filters. Then we rebuilt the turbo cause we noticed some oil leakage. rebuild kit and about 20 minutes she was back together whistlin Dixie! thanks for the reply!
Hey Wilson, I didn't see one but that is a great thought. I will check today...
UPDATE!! No good news unfortunately. But we did eliminate a couple more things. I hate to say it but I'm really leaning towards hydraulics but still not sure. Ok. We took the injectors in to have them tested. injectors were tested called for 260bar. 5 of the injectors tested at 230bar and one of them didn't hold for anything. So he said we have one bad injector which was no. 1 cylinder. We cleaned the cylinders really well and reinstalled the injectors. We will have to order one. But there was a little less smoke than before. The cylinders were nasty. I don't think replacing that injector will solve the problem though. Strange the engine is not missing. That thing runs like a champ! I don't know why if that injector is bad.... So after getting everything back together, we dug a scoop of dirt and started going through the functions. Every single function bogged engine down by half. It didn't have enough power to bring the stick in with a full load of dirt. We had to lift up on the boom to get it in. So we shut her down and pulled the lids off the hydro tanks. Inspected the suction filters, etc.. They were fine. Now I'm thinking some type of pressure relief in the main pump maybe? Even spinning the tracks brings engine down. I looked in the manual which was overwhelming on the hydraulic section. Still continue to read, but if anyone has any suggestions, I'm open. I was reading on another forum about adjusting the PRV (I'm assuming pressure relief??) all the way in to test if it was the relief. I believe the adjustment for mine is one turn out. BTW, I was asked if it does this in every mode. Yes it does. Also there are no codes displaying.
My understanding is the fuel rail pressure varies with load, so under heavy load the pressure is overloading that injector dumping fuel into that cylinder and possibly causing loss of power from early ignition. Get that injector replaced, and then see what it does. This isn't a 12 valve cummins, Jethro. You might have to call in a pro, swapping out components gets expensive if you don't know what you're doing.
LMAO! right you are on that one! Yeah best I could find that injector for was $149 B&D diesel said we could just replace the nozzle for $80 Think I'd rather go with a complete new one.... I'll have to order one today. There aren't too many places that I can find these online. I would think this would be fairly common part. I wish this was a 12 Valve cummins!
I had the same problem on my Link Belt 330, did a lot of the same things you did (even dumped all the hydraulic oil and replaced all filters) but under heavy load still blew black smoke. Finally found a shop that had a IDSS computer that would connect to the Isuzu engine and they found the EGR valve would cycle completely open and stick. I am not an engine mechanic and did not understand the connection to my problem but after they replaced it, no more smoke.
I would guess with the EGR stuck open it was dumping exhaust into the intake stream, reducing the amount of oxygen available for combustion... and since it sort of becomes a closed loop, the worse the exhaust gets, the worse the intake gets, etc...
Hey Lantraxco, Yeah I read on another forum or possibly a post somewhere on this forum about the EGR. Funny thing on this machine is I can't find one! I'm still looking through the service manual, but I'm glad you brought that up. I had forgotten to check for that in the manual. I figured it would be on the intake??? But didn't see it.
Hey Shimmy, Yeah I'm thinking overload too. I am going to replace the injector that tested bad, then I guess going through the hydraulic test procedures. I read in the manual some diagnosing steps with the console screen I can go through. It had no power yesterday, and it basically bogs the motor in half. I am thinking relief valve or something like that as well. I'm just not sure how to test yet..
Ran through the diagnostics yesterday. The errors that were popping after the test was done was saying pump1 and pump2 proportioning valves need to be adjusted or replaced. It's hard to believe both would go out. Ordering the injector from messicks today. Diesel shop wanted $410 without core and $260 with core. I called Messicks and got the injector for $107!!! Should be here Saturday. Will keep yall posted
Sometimes the computer shows errors based on faulty information, you may find a sensor is off but not out of range so the computer thinks the PV's are not working correctly.
Not being familiar with this machine I will go with the rule of thumb; Black smoke, either too much fuel or too little air.
just an update. We replaced the faulty injector. Made no difference whatsoever. Last thing to try is the injection pump. I was looking through the manual, but have not found anything about the timing procedures for this machine. When they test this injection pump and/or pull it apart, won't they put it at top dead center. I guess then the question is how do I time both components? Similar to a gas engine? No. 1 piston reaches the top? the reason I ask this is because the injection pump is just held by the taper of the shaft. There is a keyway or "Woodruff" slot with no key. I'm assuming this timing has to be dead nutz right? If anyone could provide the procedure that would be great! Thanks
Hello mate, In the absence of more qualified mechanics, I will say the lack of "key" sounds a little odd. We once fixed a similar problem where in the final act of stripping the engine in order to remove the pump (to send it for service same as you) we found that the nut holding it to the taper had come loose allowing the gear to slide about. Somehow it had jumped one tooth out of timing, too. So simply lined all marks back up ( was a geared timing set, not chain), tightened it up properly, and gave it a test run- our problem was solved. Lucky fix for us... So how is your timing gear held in correct place, if no key? Are the keyways still lined up? Can you see all timing marks? All the best.
Hi John, Good to hear from ya. The whole "Jumping" timing thing seems very legit considering the setup of this injection pump. What is odd is the tapered shaft on the pump has a woodruff key slot but didn't have a key when we took the pump off. The only thing that holds the position in place is the tapered shaft and a big nut on the end. The shaft does not move very easy. I would have thought when we were tightening the nut back on the shaft it would have spun since the only thing holding the gear in place was friction. But it didn't move..... while we had it off anyway.... that's also why I wanted the timing procedure for this machine so we can make sure everything is in time; from the pump to the engine. The injection pump would have to be at "TDC" as well as the engine is my thought. Just unsure how to accomplish this on this machine. any thoughts?
In the absence of any kind of timing marks, sometimes it's the webbing of the block casting or something vague... Did both the parts that are tapered have a keyway, and was it aligned?
One thing I was "drilled" into doing by my old dad, was when stripping down the front end of an engine, to line everything up to top dead centre before starting and check out the current timing position and mark it fresh if necessary, before undoing anything. Even to the point of locking or fixing parts in place somehow, on occasion. Then at least you have these points of reference for starting rebuild. If you put a serviced pump back on in the same position, you can then alter the timing if necessary from these marks, but usually it runs fine from these marks. You can put the engine through several revolutions are the start of necessary (before strip down) to understand the timing positions. There are various ways of finding top dead centre, did you try yet? For marking we use dots of white paint, or centre punch paired dots, or a sharp line filed across some edge where it makes sense. All the best. John
For specific instructions on kobelco timing, the only person I have come across who seems to have access to this info is Adam Fairchild, H F Hydraulics. You can google this if you want. Have your serial number handy if you do contact him!
sk250 hydraulics loading engine Kevin Armentrout, did you ever figure out what was wrong with your machine? I have a sk250 with the same problem. Thanks in advance.
My SK 250 had a turbo waste gate that was vacuum operated. It was blowing heavy black smoke when under heavy loads. The waste gate on the turbo was froze up. Just a thought
Such a shame to read through 3 pages of post / ideas and then not have an answer to what the problem was.....
sk250 I'm pretty sure it is not the waste gate. The turbo was just rebuilt by the guy I got it from and the waste gate actuator apparatus looks new. It was hard to move by hand but the actuator arm did move so the gate is not stuck.
Have you plumbed a gauge into the intake to check boost pressure?? If the turbo was "rebuilt" by the previous owner that's all the more reason I would suspect low or no boost as the culprit.. Without running through basic diagnostics you are just playing the guessing game.
sk250 No I have not checked boost pressure but I did pull line off and checked turbo. Fins looked brand new and it turned by hand very easy and smoothly with no slack. It was rebuilt by a shop that rebuilds turbos everyday so I would assume it was probably done right. BUT I know what assuming about someone else's work can sometimes get you.
Hey guys. Usually I get an email if a new post happens. The sk210 is still not fixed. We just took off the main relief and cleaned it up. No difference. Took off proportion valve 2 and cleaned. Tested the poppet and seems to work fine. Running through the diagnostic mode 1 and 2. Diag mode 1 shows Diag mode 1 result 1 Engine NG EGR sensor NG Diag mode 1 result 2 P1 pump NG P1 pump psv NG And the same for P2 Where to go from here....
Still nothing Still no solution bud. Still working on it. Sorry for no update in a while..
keep us posted!! Interested to see the solution...cheers
Has 2 more months brought a solution?
Still waiting on a serial number or picture of the engine and fuel injection system, unless I missed it.