Oil & Fuel B9200 won't stay running

[chasrico]

Hi all....new member here.

I have a B9200 HST that won't stay running. I think it's fuel related but after after testing and trying many things I still have the same problem. Any thoughts on this would be greatly appreciated.

Symptoms are - Starts, runs and operates (moves dirt w the FEL and travels well at all throttle ranges) normally for 10 - 15 minutes. Minimal smoke at start up and no smoke while operating. Then it starts to lose power, the rpms fluctuate and then stalls. At this point it becomes hard to start and will not stay running at all. If I let it sit a couple of hrs it will start and run for another 10 minutes or so and then dies. I've repeated this process now a half dozen times with the same results.

What I did to correct this. In order
-Replaced the fuel filter. Which was clean.
-Checked the condition of the fuel and tank.No water and minimal rust inside the tank.
-Checked the fuel flow from tank to filter, filter to lift pump, lift pump to injector pump and cracked the fuel pipes to the injectors. There seemed to be plenty of fuel getting to all of these points.
-Changed the oil. There were no signs of fuel, coolant or metal in it.
-Took the injectors to a rebuilder (D&W diesel). They tested them and said they were in surprisingly good condition for their age. They did not think it was an injector pump issue and suggested I look at the lift pump.
-Replaced the lift pump.

I still have the same problem and I have no idea where to look next. Not sure, but I think I've covered the fuel related areas. One mechanic suggested that it might be a valve issue which would mean taking it to the dealer which I want to avoid if possible. Again.......would appreciate any ideas on this.

 

[whis]

blockage in the fuel tank

 

[DT86]

blockage in the fuel tank

Or fuel line. I had a similar problem and it turned out there was straw stuck in a 90* elbow near a filter. How it got there I can not say as I've never ran without a fuel cap.

Blow compressed air from the first break in the fuel line back into the tank and see if that clears it up.

Report back.

 

[chasrico]

blockage in the fuel tank

Yes...... I took the tank off and flushed it w water. There was no blockage. Before reinstalling it we blew compressed air thru the fuel line between the filter and tank. After this we rechecked the fuel flow from the tank to the filter and from the filter to the lift pump. The flow was strong. Started the tractor and it ran well for 10 minutes before losing power.

 

[npalen]

Is it possible that the fuel hose may be collapsing somewhere after a period of time with heat?

 

[chasrico]

Is it possible that the fuel hose may be collapsing somewhere after a period of time with heat?

When the tractor started to stall we checked that. There are 2 short rubber hoses, 1 between the filter and lift pump and the other from the lift pump to injector pump. Took both of them off and looked thru them and they were wide open.
The 1 hose I did not check well was the small diameter line that carries the excess fuel from the injectors back to the tank. I am thinking to test that by disconnecting it at the tank with the tractor running. I should have fuel returning to the tank. But I've never done that and am not sure what the flow should look like. I assume it should be pretty steady. Not sure.... but I think if that was blocked i would have a visible leak somewhere or the injectors would not be working well. I'll try this later and see what happens. Who knows....maybe I'll get lucky.
Thanks guys....for the responses.

 

[twinponds]

I had the same problem on my b9200 last year. Ended up being a sporadic collapse of a fuel line. Your b9200 is probably 25-30 years old--its fairly cheap to replace all the rubber fuel lines and when you do make sure you use lines designed for diesel. I would imagine you also checked to make sure nothing is getting pinched by the seat or some debris. I also assume you had the same problem when you run the tractor with the gas cap off and that you are bleeding the air out of the fuel system per the manual and also by slightly opening the fuel lines going to the injectors. Good luck.

 

[npalen]

I'm anxious to hear what is causing the problem as I have a B9200 also and, yes, they are becoming elderly. I can't say enough good things about this little tractor. They are a beast! Using the old cliche, "they don't build em like this anymore". Very little electronics to deal with.

 

[chasrico]

I'm anxious to hear what is causing the problem as I have a B9200 also and, yes, they are becoming elderly. I can't say enough good things about this little tractor. They are a beast! Using the old cliche, "they don't build em like this anymore". Very little electronics to deal with.

Yes Npalen......this has been a great tractor for me too. I've owned it for 16 yrs now. I have about 2 acres to maintain and it does a little bit of everything. From snow removal to cutting grass to transplanting trees......don't know what I would do without it

Twinponds.....
- hooked up a secondary fuel tank directly to the transfer pump. Bypassing the tractor tank, steel fuel line and filter. Had the same results.
- You're right about 30 yr old rubber hoses. They look good but I'll replace them. Didn't know there were hoses designed for diesel.
- ran it with the fuel cap off. Same results.
- been bleeding it with valves on the inj. pump and filter assembly. Seems to work well. I haven't had to crack open the injector pipes.
Also tried
- checked the rubber fuel return hose from the injectors back to the tank. I was looking for air bubbles in the fuel but there were none. There was no steady fuel flow. Just steady drops. But I'm assuming this is normal for the fuel return to the tank.
- disconnected and clamped the return hose at the tank while running the tractor to see if the back pressure/fuel flow to the injectors would somehow affect the performance. It didn't....lost power and stalled after 10 minutes running.

Thanks a bunch for the input!!!!

 

[Harry in Ky]

Seems you've covered most of what can go wrong with little success. You say you checked fuel flow from return hose into tank and found very little, if any flow. No air bubbles. That sounds like what one would expect from the injector return line. I think the pump return, however, since it has a supply pump, should have at least a noticeable return flow of it's own. You could try removing the return hose from the pump, installing a short hose in it's place and placing the open end into a can or bottle to check the actual return flow at that point, separate from the injectors. I see you tried the external fuel supply directly to the supply pump. I use that trick myself when supply is in question. There is still the supply pump itself. You stated it has been replaced as well, but I still wonder about it's effectiveness. While the extra fuel return hose is on and flow is being monitored, I would observe what is exiting while the engine is running, then maybe shut the engine off and remove the supply pump. Operate it manually and see what if any difference that makes in flow of fuel out the return. I would think if the supply pump is working, you should see a pulse of fuel with every stroke whether the pump is mounted on the running engine or operated by hand.