BX2200 start problem

[Nico01710]

Hi all,

I had an unusual problem with my BX2200 this morning.
Here's what happened:
Go for start, ignition turns on (light ok), preheat a few seconds ok, go for starter, engine starts immediately but then stops as soon as I let go of the starter back to normal position (ignition).
I tried starting it many times but the same thing happened every time...

Anyone have an idea of what the problem might be? Would prefer to try fixing it myself rather than getting the service people on it...

I've never had any problems with this tractor. It's 9 years old but only 200 hrs and it's just been serviced (about 10 hrs ago)

Thanks for any advice,

Nico

 

[NY_Yankees_Fan]

Nico,

:welcome: to TBN

Check the fuses in the fuse block on the right side behind the black intake screen. My guess you have a blown fuse.

 

[RaydaKub]

Just curious if you heard the shutoff solenoid click in or not (loud click a few seconds after the tractor died). If you heard it click after the shutoff, it would seem to me you have a short in the electrical somewhere. It starts fine indicating the shutoff is not activated while the key is in the start position, but then the run position might be triggering it for some reason. Pure conjecture on my part of course.

 

[Nico01710]

Hi Guys,

Thanks for the replies.
Ok, so I checked out a few things on the tractor and a few other threads on the web.

1. Fuses are all fine. None are blown.
2. It seems the fuel shut-off solenoid has a weird operation. It has a 3 pin connector (one ground and 2 different positive wires). Apparently it pulls the pin (which allows the fuel flow) once when you crack the starter and then has a secondary winding that 'holds' the pin in when you go from the 'start' to 'ignition' position to maintain the fuel flow on.
When you turn the key to 'stop' the current is cut to the 'hold' circuitry in the solenoid and that sends the pin back out to the shut-off position.

I checked this out with the solenoid dismounted from its housing and, indeed, when I quickly put the key to the 'start' position, the pin is pulled (which would allow the fuel to flow and the engine the start normally). However, when I released the key back to the ignition position, the pin was not held and it went back to it's original position (out). And this would explain why the engine starts normally but then dies as soon as you return to 'ignition' with the key.

Voltmeters tests seem to corroborate a faulty solenoid as the 2 circuits ('pin pull on start' and 'pin maintain pulled' on ignition) tested OK on the solenoid plug connector (on the wire harness side), meaning 12V is read correctly in both instances.

So, all that to say, looks like it's the solenoid that gave in... Pretty weird as the tractor only has 250 hrs. It is 9 yrs old tho...

One final thing if I may: I am amazed at the price of these small spare parts... $150 for a fuel shut off solenoid...!! I mean its only a cheap metal housing with some copper winding in it! They must really make a fortune on those things.
Maybe I should go into the solenoid manufacturing business! :thumbsup:

Sorry for being so long on this reply but thought it might some day be interesting for someone else.

Nico

 

[Nico01710]

Hi all,

Quick question. As the guys are telling me it will take 3 weeks (...!!) to get a new solenoid, I was wondering if it would be a good idea to bridge the 2 solenoid circuits in order to send current to the 'good' winding even with the key in the 'ignition' position.

Since the solenoid works properly in the 'start' position, my guess is that connecting the two 12v leads together will constantly keep the working winding under current and keep the fuel flowing.

Only thing is I have no idea if these windings have a different resistance and it the circuitry will hold...

Anyone think this is a bad idea?

Nico

 

[RaydaKub]

Hi all,

Quick question. As the guys are telling me it will take 3 weeks (...!!) to get a new solenoid, I was wondering if it would be a good idea to bridge the 2 solenoid circuits in order to send current to the 'good' winding even with the key in the 'ignition' position.

Since the solenoid works properly in the 'start' position, my guess is that connecting the two 12v leads together will constantly keep the working winding under current and keep the fuel flowing.

Only thing is I have no idea if these windings have a different resistance and it the circuitry will hold...

Anyone think this is a bad idea?

Nico

Me. You say the solenoid is working in the start position. That is in incorrect statement. The only time the solenoid is energized (and thus "working") is during the shut off. It is dead hardware during run time. So at this point, I'm thinking either a short in the wiring or more likely, the switch itself.

 

[Nico01710]

Hi RaydaKub,

Sorry but what you're describing is wrong. The solenoid is energized during engine running. Turning the key to off cuts the current to the solenoid which then sends the pin back out (spring loaded) to push the fuel shut off slider in the injection pump.

So, technically as I mentioned before, if you send current constantly to the solenoid via the 'start' circuitry, it will maintain the pin inside and let the fuel flow to the engine.

That being said, I just found out on the web that the 2 windings have very different resistances. The 'Pull' winding will draw about 30 amps whereas the 'Hold' winding will only draw about 0.7 amps. So bridging is probably a bad idea since it might just overheat and burn the wire harness...

Oh, and, I found a much cheaper solenoid on Ebay: $75 with FedEx delivery under 4 days. Seller rating is excellent so I'm gonna give it a try.

Nico

 

[RaydaKub]

OK, I'm certainly not an expert, but these diesel engines don't need the electrical circuit to run. If you search the threads you'll find several that talk about "help, my tractor won't shut off". There was one rather heated discussion last fall about it (of which I was on the wrong side and have come to see the light). I'm not sure what you are measuring, but the shutoff solenoid only becomes energized for about 15 seconds to kill the fuel pump flow. During run time, the solenoid is not energized.

Picture yourself running a big tractor with a large load on a wagon going down a hill. The fuse blows and the solenoid "stops working" and shuts off the fuel. Not a good plan.

That's why they are NOT designed that way and only trigger when it's time to shut off. They are not necessary for the tractor to run. And there is a red tipped lever on the fuel pump to manually shut it off in case the electrical does have a problem.

 

[Nico01710]

Well that might be the way large tractors operate but it's not the case with small Kubota tractors.
Here's a thread which will explain things:
http://www.tractorbynet.com/forums/...157994-b21-starts-then-stops-immediately.html

The operation is 2 fold:
On 'Start' the primary winding in the solenoid pulls the pin and releases the fuel flow
On 'Ignition' the primary winding is shut off and the secondary winding holds the pin in place (meaning retracted in the solenoid)
On 'Stop' the current is cut completely and the solenoid releases the pin which then pushes the fuel shut off in the injection pump. The system stays like that until the next start.

Nico

 

[Wood_Butcher_Dav]

I have the same issue, bad solenoid. My band-aid fix was to remove solenoid and make a plate to cover. Now to shut off the motor I just choke it out (lever or butterfly valve). I did this last year when sticker shock hit for what they want for this soleniod.

Dave