My Thomas 173 stalled and now it will not start. 2200 hours on the machine. 135 hours on the fuel filter. I opened the fuel injectors, one at a time, and tried to start the motor. No fuel at 3 of the injectors. Fuel at 1 injector.
I have a manual for a 133 which is likely similar. It lists quite a few reasons for a no start but here's few of them that could be linked to fuel issues. The lift pump, blocked fuel feed pipe, blocked fuel tank vent, broken injection pump drive. If it starts and stops they list choked fuel filter, restriction in air cleaner or air in fuel system. I'd try a few simple things first like taking the fuel cap off or blowing the fuel lines out. I assume it has a Kubota so the 1 thing you don't want to do is use ether on it. A mechanic told me Kubota's have very tight tolerances and to never use starting fluid/ether on them.
Check to see if your getting fuel TO THE inj. pump.. If you have fuel INTO the inj. pump & nothing OUT.. its more than likely the pump.. or a real big slug of air. Open the lines AT THE INJECTORS all at once & see what your getting.. if its air, it'll bleed faster w/ ALL of them open at once.
Yes it’s a kubota. I didn’t think of blocked fueltank vent. I blew out the fuel line from the tank to the filter. No fuel getting to the injector pump.
I may be mistaken but I "think" it has a lift/supply pump in the system?? Follow the lines.. its gonna be between the fuel tank & the inj. pump.
some kubotas have a valve on the return line and a primer bowl as well . Manual says to open that valve and prime it till the bowl is firm
If it's like mine (94) there's a knob you loosen to bleed air but it's still not the easiest engine to bleed air. Changed fuel filter once in a little colder weather and it was a real pain to bleed it. Ended up taking a small fuel line off and slowly putting fuel down it. Now I always run it first before changing the filter. They say not to fill the filter first and that' makes it harder to bleed too.
Doesn’t matter when you last changed the filters. Your not getting fuel so first then no to do is change the filters.
Thanks for the replies. Yes, there’s a lift pump between the filter and injection pump. Yes, there’s an air bleed value but no primer bulb. NOT to fill the filter when replacing it seems weird? I’ve ordered a filter.
I think the reasoning not to fill the filter is because the fuel you put in won't be filtered.
Good point. I checked the repair manual and it doesn’t say either way. Lube seal. Install filter. Open tank shutoff value. Remove air by bleed value.
It’s still not starting and it’s cold and snowing outside. Can I tow/drag my Thomas 173 fifty feet to my shop? What needs to be done? Lower the seat bar? Or is it best to fix it in place?
Finally got it running today. I installed a primer bulb in the fuel line as well as a new fuel filter. It took longer than expected to get fuel to the injector pump as well as to the injectors. Then it ran poorly and slowly improved as it worked the air out. All good now. Many thanks for all the help.
glad its all fixed.. I know my kubota motor on my bobcat has an inline primer and was surprised yours didnt