B2410D

[Wull]

Kubota B2410D fitted with a D1105 engine.

Bear with me I’ll give as much info as possible so it will be a long post. Tractor is a friends.

Complaint was he would be cutting his grass and it would start to lose power after a few minutes of use, it would never cut out but would lose power. Sometimes he would switch it off then back on and it would be running rough, he also said when it happens he starts to get some smoke out of the exhaust.

My first thought was fuel starvation so went to have a look. The fuel supply to the filter is good, it pours out when you remove the fuel hose to the the filter, I removed the hose that goes from the filter to the mechanical lift pump and it pours out. I checked the filter which was good other than discolouration but put a new filter in anyway. The lift pump works as it should, I removed the fuel hose that goes from the lift pump to the injection pump and when cranking the engine it spurts out fuel as it should.

At this point I’m happy that it is not a fuel supply problem as such with regards to flow.

We ran the tractor and it was great for about 3 mins no problem then put the PTO on and it ran for a further 3 mins or so before it started to run poorly, I suspected at this time it was as if it was running on 2 cylinders. I started to open the fuel lines to the injector nozzles and when I cracked open the connector at cylinder No.1 the rpm’s did not drop, there was fuel when I opened it but it did not affect the running of the engine. I closed it off then cracked open cylinder no.2 and the rpm’s dropped and it was running rough, now running on 1. I repeated the same process for no.3 and the same thing happened, the rpms dropped and was running poorly now on 1.

At this point I suspected the injector nozzle on 1 to be faulty so we replaced that. The tractor ran great for about 3-5 minutes no probs then a further 6 minutes with the PTO on before doing the same as before. It was doing the same before with regards to cracking open the fuel lines except this time it had moved from 1 to 3, he had switched the tractor off and at one point it would not start, I cracked open the fuel lines again and there was no fuel, but there was fuel supply to the pump. So I removed the fuel cut off solenoid to rule that out and the tractor would still not start. I think in this moment it was just needing bled as I think ( trying to remember back ) I had removed one of the fuel lines, maybe checking the output from the lift pump again.

I was suspecting the injection pump at this point, so we got a reconditioned one and fitted that. I wasn’t convinced though as the one I removed the fuel rack was nice and loose working as it should and each plunger moved up and down as it should but he said to get one anyway. So with the new one fitted it’s doing the same.

I’m now fully convinced it’s drawing air in, but it seems to only do it after x amount of minutes, I’m wondering if the lift pump is drawing air in, I can’t see where else it could come from, all fuel lines are good and the return lines seem good, one is slightly deteriorated but not enough imho to cause any problems, I think I’ll replace that one anyway just to rule it out.

When it wouldn’t start and or was running very poorly towards the end and no matter how much I bled it it wouldn’t run any better, I was really starting to suspect air in the system at this point. Each time I cracked any lines there was visible bubbles and it just didn’t seem to improve. After shut down I removed the lift pump and when I removed the line from the pump to the injection pump there was a fair bit of gurgling and air noise, I’m not sure if this is just simply fuel returning back down from the pump and the return line or whether it’s a noise due to air getting drawn in.


This one has got me. Has anyone had experience with a lift pump where it’s been drawing air in even more so after it’s warmed up?

And for clarification, this tractor has fuel supply from tank to a fuel filter ( filter housing has no bleed screw, but a hose from the top that goes to the tank, then it goes to the mechanical lift pump ( no lever ) and then to the injection pump.

Cheers

 

[Wull]

I’m now wondering if there is water in the fuel as it doesn’t have the fuel water separator bowl, to be honest i didn’t have that in my mind when i was looking but there wasn’t any obvious signs of water but i suppose i can’t rule that out, i had planned on supplying fuel separately from the tank to rule out fuel supply as the culprit but haven’t got round to it yet.

 

[Mountainman]

Water would be my thoughts. Try to drain it all and get some fresh fuel in there and see what happens

 

[North Idaho Wolfman]

Where did you get your injectors from?
Where did you get your injection pump from?
Did you reinstall all of the shims under the new injection pump?

If you want to eliminate all the fuel delivery issues bottle feed the injection pump.
If it runs properly then you have a fuel delivery issue.

Water and Gasoline in the fuel can cause all sorts of issues, you would be smart to replace all the fuel with fresh fuel.

 

[Wull]

Where did you get your injectors from?
Where did you get your injection pump from?
Did you reinstall all of the shims under the new injection pump?

If you want to eliminate all the fuel delivery issues bottle feed the injection pump.
If it runs properly then you have a fuel delivery issue.

Water and Gasoline in the fuel can cause all sorts of issues, you would be smart to replace all the fuel with fresh fuel.

I’m going to drain the tank tomorrow to check for water etc and supply the fuel separately to see if it runs fine or does the same.

the injector nozzle was from a parts supplier so genuine item. The reconditioned pump is from a company over here in Scotland called JEM ENGINES who specialise in Kubota etc. Shims all replaced as it was before.

 

[Wull]

Update on this.

I went on Thursday and drained the tank, I put some of the fuel in a clear jug and did the same with some fresh fuel and the difference visually was massive, I can’t confirm that it had water in it as I wasn’t getting the usual separation but it just looked crap in comparison.

I then supplied fresh fuel via a container to the lift pump and we got the tractor going and it ran great for 25 minutes before we had to stop as the container was running low on fuel and the container I was using for the return line was almost full. This was a success as it never ran for more than 6 minutes before playing up.

The owner inspected the tank and felt it was clean enough visually, no signs of water or any other contaminants so his plan was to put fresh fuel in and test it by cutting all his grass. He contacted me the next day and says it started then cut out and wouldn’t start again. So I went there today to have a look and there was no fuel getting to the pump, I removed the line going from the lift pump to the injection pump and whilst cranking there was no fuel at all, a dribble at best.


So I removed the lift pump and it works when you activate the arm by hand, but when in place it won’t work at all, never more than a pathetic dribble, has anyone had that before where it’s failed in such a way that it won’t work when in place but will work when removed? He’s told me to get another one anyway but I’m worried the replacement will do the same, I was thinking maybe the lobe which activates it has worn enough not to activate it or the lever itself has worn but there is no visual signs to back this up.

I suggested we fit an electric pump to bypass this altogether, has anyone done this with success? Low pressure fuel pump, I’m sure it would be fine but any feedback on this would be appreciated.

 

[Wull]

I put the replacement lift pump in yesterday evening and it was spurting fuel out as it should, tractor fired up quite the thing.

He’s going to wait until the weather is slightly better before attempting to cut all his grass, when he does that we’ll know for sure whether the original problem is fixed, fingers crossed.

 

[Wull]

Another update.

I replaced the lift pump with a new one, he stuck the fresh fuel in and it’s now working a treat. He’s pleased he can get all his grass cut easily now so that’s a good result.