Oil & Fuel dk45s injector pump problems at 500 hrs

[Coyote machine]

Another issue that pertains to this discussion is the fuel additive / fuel quality debate. IPs are close tolerance precision parts that work well when made from the highest quality materials and close inspection of their manufacturing process, to insure few if any defects. Coupled with the ULSD fuels available to the public these days any variation in material workmanship, or the possible expectation on the part of the pump manufacturer that the end user will supply lubricity via additives can make the wheels fall off the wagon. I surmise that the pump manufacturer and Kioti /Bobcat, etc. know exactly what is happening and for whatever reason look away when things go wrong, especially off warranty or at low hours on any machine they sell.
Suppose, as some have said that the problem is gears made from too hard a material. That can be remedied fairly easily- but then one doesn't sell as many pumps. Though selling more pumps is a double edged sword- defective parts are a source of more part sales BUT the ones replaced under warranty are in theory charged back to the pump manufacturer from the tractor manufacturer and both can suffer a resulting bad reputation for having problematic parts that render the customer unlikely to be brand loyal. This is bad for business. This is where I fall down in understanding the mentality that allows quality to suffer at the expense of customer satisfaction. I get the whole, look at the economy and the cost of manufacturing and competition scenario, but if one makes a better product that is less likely to break, and builds a solid reputation for reliability, then this company will win out in the short and long run by selling more product and building their reputation one loyal customer at a time.
Bottom line for me is maybe the use of a lubricity additive is necessary to keep marginally quality parts from locking up like the IP racks that sometimes jam, but it will not cure erroneous material choices that fail due to being too hard or brittle to withstand the pumps internal movements.
So until Bosch/Doosan and or Kioti put their collective brains on this problem we'll all be walking on eggshells around our IPs hoping the warranty clock doesn't time out before a possible failure, and huge expense.
I say BOGUS to Kioti and Bosch/Doosan. FIX IT!

 

[ritcheyvs]

The main failure mode is teeth getting ripped off the IP gears by the force of the stop-solenoid spring. These gears and the rack teeth are lubricated by motor oil, not fuel. So I doubt fuel, lubricity, or additives are a factor in these failures.

 

[Coyote machine]

The main failure mode is teeth getting ripped off the IP gears by the force of the stop-solenoid spring. These gears and the rack teeth are lubricated by motor oil, not fuel. So I doubt fuel, lubricity, or additives are a factor in these failures.

Good point and thanks for the correction. I was thinking about the fuel delivery and close tolerances of the injectors and atomization of fuel and not about how the oil from the sump is the lubricant for the rack , etc.
Duh, this is what happens when I consistently stay up too late and think about things or try to write.....:confused2:

 

[seacap04]

I have an 07 DK45. Every now and then I have to go through the start sequence a couple of times to get it to start. When this happens I can't help but wonder if this is the time I will have to replace the IP. Not a warm and fuzzy feeling. I can not thank everyone enough for helping to document this issue and find the best way to repair it. At least now I know what to look for.

 

[ritcheyvs]

Ditto except mine cranks right up every time ... so far except once. I have learned much tracking the efforts of others with this issue. When these IP gears go, the IP dies completely, usually jammed in the full off position although jams in the full on position have been reported also.

Your slow start problem could be a weak glow plug or small air leak somewhere on the fuel feed side. Misadjusted valves (too tight) can make cold weather starts hard too. I did have one cold start problem that was caused by a dirty ignition switch which interrupted the "glow" signal when I turned the key to the crank position; sometimes the engine would "catch" just as I released the switch back to the "on" position. Slow starting is not typical of an IP problem.

One good thing is that this particular IP failure mode (broken gear) is easy to diagnose visually, you just need to remove the oil fill cover plate just below the IP. I didn't understand this when Sherrym first had the problem so that diagnosis was unnecessarily convoluted. If the IP is working right, the rack pin should be to the left and the inner lever to the right (with a gap between them) when the key is in the off position. When you switch the key to the on position you should hear the loud click of the stop solenoid retracting and the rack pin should move to the right and rest against the flat vertical face of the inside lever. You don't need to run or even crank the engine to do this test. If you don't hear the stop solenoid retract there is an electrical or mechanical problem with the solenoid. If the stop solenoid is good and If the rack pin doesn't move, the IP is probably jammed (failed) internally.

 

[seacap04]

I orginally had a "dirty" plug off the start switch. That symtom was that the engine would not crank over. Now the issues are every now and then It will fire up and die one to three times whether the engine is warm or cold. Or it will crank over a couple of time and not fire at all. From this forum I have learned to listen for the click from the fuel solenoid which it does everytime whether it starts or not.

 

[Coyote machine]

I orginally had a "dirty" plug off the start switch. That symtom was that the engine would not crank over. Now the issues are every now and then It will fire up and die one to three times whether the engine is warm or cold. Or it will crank over a couple of time and not fire at all. From this forum I have learned to listen for the click from the fuel solenoid which it does everytime whether it starts or not.

Sometimes my DK will crank but not start. If its cold I just turn off the key and wait until its full cycle glowed- light out, then crank again. If its at operating temp and it doesn't start on first crank I turn off, then on, and crank and it usually starts. As stated these type of no start conditions are not IP related- so nothing to worry about.

 

[sherrym]

The main failure mode is teeth getting ripped off the IP gears by the force of the stop-solenoid spring. These gears and the rack teeth are lubricated by motor oil, not fuel. So I doubt fuel, lubricity, or additives are a factor in these failures.

scott,

I watched the action of the stop-solenoid after we put new part on through the oil fill cover and I thought it was more violent than it needed to be just by watching it. Therefore, I think the enginneers need to determine if this process is excessive and try to fix by either a less violent SS or material in the IP that can withstand the SS action.

Also when talking to mechanic at texas dealership he ask if we ran tractor when low on fuel saying that could cause excessive heat and he felt that could also have something to do with the teeth breaking. I did not totally understand how low fuel could cause overheating, but we do not run tractor low on fuel.

 

[sherrym]

Sometimes my DK will crank but not start. If its cold I just turn off the key and wait until its full cycle glowed- light out, then crank again. If its at operating temp and it doesn't start on first crank I turn off, then on, and crank and it usually starts. As stated these type of no start conditions are not IP related- so nothing to worry about.

My husband also reported a few times of starting problems and felt the starter did not engage the flywheel on first try but then on second try tractor would start. He said this happened a few times over a two year period before IP broke, and mainly happened in warm temp. Would mention though, the day before IP broke we were picking up bales of hay with tractor and at one point it was turned off and when restart after 3 mins. it cranked but would not start. Tried a second time and it started.

Also Scott may want to put in information he is collecting, on what the tractor is mainly used for. We mainly use our kioti for mowing, raking, and collecting square hay bales. Occasionally we use it to bale the hay. This year in particular the weather was extremely hot when we were using tractors for haying. The little ford (for tetering) and the big JD for baling were also used with no problems. The temp. gauge on kioti showed fine while we used it so husband doesnt feel temp had anything to do with it. Just a thought since the texas mechanic mentioned overheating as a possible cause of broken teeth on IP.

 

[ritcheyvs]

I watched the action of the stop-solenoid after we put new part on through the oil fill cover and I thought it was more violent than it needed to be just by watching it. Therefore, I think the engineers need to determine if this process is excessive and try to fix by either a less violent SS or material in the IP that can withstand the SS action..

I suspect this is the real answer. The old design applied solenoid force to the rack pin via a shaft and two linkages and that certainly absorbed some of the shock load. This new stop solenoid design appears to have excessive spring force applied directly to that rack with no damping or shock load buffering. So we are probably dealing with excessive SS spring force and marginal gear tooth toughness that all adds up to broken IP gears.

Also when talking to mechanic at texas dealership he ask if we ran tractor when low on fuel saying that could cause excessive heat and he felt that could also have something to do with the teeth breaking. I did not totally understand how low fuel could cause overheating, but we do not run tractor low on fuel.

Personally, I use fuel additives in my Diesel engines, both a biocide and a conditioner, like Power Service (mainly because it's easy to find). But I doubt this has anything to to with this current problem.

The IP plungers and cylinders are machined to very close tolerances (they are matched sets, plungers are generally not interchangeable between cylinders) and they are lubricated and cooled solely by fuel. So running them dry will absolutely damage these precision parts. But the engine would stop running long before this happened unless only some of the plungers ran dry. These plungers travel their full stroke up and down every other turn of the crank shaft so they are moving up and down all the time. The rack and gears are constantly rotating the plungers to regulate engine RPM. I just can't rationalize how "sticky" plungers can be the culprit.

Most of the reported failures happen when the engine is switched off which means the SS successfully moved the rack to the off position. So maybe it's the abrupt stop in the full-off position that's the real cause here.

 

[mashyken]

I own a 2006 Kioitdk45s with Cab, and KL451 Loader. I Purchased it new - and when new the fuel injector pump broke and the engine ran wide open. I stalled it out with high gear and the brake as the key was not able to turn it off. I was able to get it home as I was not far away. The dealer came took it away and replaced the fuel pump. While it was there, I had them put a cable operated shut off on it in case it happened again. During the warranty, the shuttle shift also failed to operate. They took it away again, removed the cab and split the tractor to replace the shifting forks. Apparently they had some units with soft steel in those forks, and I was fortunate enough to have one of those tractors.. Also, when I got it, the electronic PTO kept blowing fuses. The first winter I went through about 15 fuses when blowing snow. It was the following spring that the shuttle shifter caused the problems and when they removed the cab, they found a pinched wire and this was the cause of the blowing fuses. It has not blown any more fuses since this fix. Several years later, now 2012 - with 550 hrs - the tractor quit again, this time with a 24 ft pontoon boat on the trailer behind, on a narrow road. The engine stalled out, and would not start. I was barely able to get the trailer unhitched and the tractor off the narrow road to pull it home. The dealer said they suspected it was the fuel pump, drove 3 hours as there are no Kioti dealers close to where I live, they arrived with no parts in hand. They determined this was the problem, a broken fuel pump. They left, ordered a new pump and returned two weeks later. After installing it, and no running engine, they determined that the BRAND NEW pump was defective - removed it and returned home. They came in another two weeks with a second NEW pump, and installed it - AGAIN DEFECTIVE - and no starting. They returned home again and came back a third time with their truck to take it to their shop. FINALLY - they got it running. They asked me if I wanted to trade it in on a new unit. After six years, it only has over 500 hours on it. I am not too keen on buying another Kioti after having these issues. A mechanic friend told me I should be running a fuel additive as the fuels today do not have the lubrication in them the older fuels did and this additive will help lubricate the fuel pump. I am now running the conditioner, however the machine only has few hours on it since it was returned with the new fuel pump. The shifting was also sloppy in the levers, (it is a geared transmission) so I had them check the forks and they replaced those via the side panel without having to spit the tractor. I was very surprised at the amount of wear in them for such a life span. It confirms to me, that yes, these are cheaper tractors to buy, but you get what you pay for. I love the way this tractor works, and the features it has over Kubota (the rear three point hitch lifting handle is great for a cabbed tractor to have) and it works hard and is strong, but having these kind of problems - well - it was not worth the savings I made over buying a large brand name. I did buy this tractor as I height is perfect with the Industrial tires to fit in my garage, and I like the 12 forward and 12 reverse and the shuttle shift, plus the way it was put together and thought out. I am very disappointed in the mechanical problems it has had as I purchased a NEW tractor to avoid having those head aches. What I have also found, when trying to trade it in - some dealers do not want them, and those that will take it, are really low balling the value - it could be that the prices on new ones have dropped? Anyway, live and learn. I figured I saved thousands over the larger brands and it had features they did not have - but I have paid well beyond that in repairs and down time. This last bill, was a few dollars shy of $4,000 (including a full service)- I am hoping I now have all the bugs worked out of it. So much for buying a new tractor to avoid problems!

 

[ritcheyvs]

mashyken: Can you supply the year and approx operating hours when the original injection pump failed? Also, if you provide the first four digits of your serial number, that would establish your exact model.

Also, can you clarify if the second failed fuel pump was the injection pump (expensive) or the lift pump (relatively cheap)? If injection pump, can you give the year of that failure? Considering that they tried three "bad" replacement pumps (pretty unlikely) the second time, do you suspect the real problem was something else (e.g. misdiagnosis)?

For my own curiosity and to aid other Kioti owners, I'm compiling injection pump failure data from TBN posts:
http://kittrellcommunitywatch.dyndns.org/Kioti_IP_Data.htm

Thanks.