This problem is a real pain. I help out at my kids school by cutting grass with their old Jacobsen Flail mower. I have to drive it a 1/2 mile to the fuel tank. I fill it up and it will not restart. It will crank over, but not start. Now I have to hike back to my truck and get jumper cables to revive it. I've tried leaving it running and it will shut down when it gets near full. I have to wait 10 or 15 minutes before it will restart. Craziest thing. I'm wondering if it has to do with tank venting or loading on injection pump fuel return line? What do you think?
I think I'd be siphoning out the tank to see if there's any debris or floaters in there, cause I can't think of anything else.
That's a good idea, but this happens with precision. Only when the tank is full does it go dead if running. I can fill 3/4 tank every time and no problem. I really suspect its back pressure on the fuel return line or some similar weird thing. This morning the machine left me stranded for 20 minutes + the walk back to the truck. This thing is parked under roof or I might buy water in fuel???
I'm more inclined to believe that there is something like a plastic baggie or some other solid, semi floating, debris in that tank.
do you always have to jump it to restart it? if you do, seems odd as the fuel/battery aren’t linked obviously maybe use fuel containers in the meantime so you don’t have to walk back so far.
Tank venting problems would be be more pronounced with a full tank but should also happen at partial tank also, I am presuming that you have left the fuel cap loose to eliminate that as a possibility, as far as the starting is concerned does the cranking become slow as if the battery is discharged? If so and the cranking is greatly increased by jumping it is it possible the voltage is dropping so low that the fuel solenoid is not opening without the voltage boost, that does not explain why it shuts down when the tank is being filled, That is assuming that it has a fuel solenoid on the injection pump, Is the charging system charging the battery properly, are the battery cables in good condition and the battery in good condition, slow cranking tells me that there is an electrical issue, how long cranking before it starts to crank slow? Just trying to get as much info so we all can put our heads together, got some really sharp minds on here but we need as much info as you can give us, thanks. Just a thought, does it have a bleed valve on the injection pump inlet fitting? I once went on a call for a Kubota that was not running smooth, shutting off, giving all sorts of problems! The knob was missing off of the filter bleed valve and there was just a stem sticking out. snapped some vice grips on it and seated that valve and presto, just like a new tractor. That valve open defeats the charge pump as fuel coming from the pump is diverted right back to return, maybe the back pressure of a full tank is enough to overcome the supply pump if it's volume is being diverted to the return, Maybe not but it is a thought to pursue.
My bobcat 753 has a Kubota V-2203 engine. Every once in a while the shut off solenoid won't engage when I turn the key on. If I leave key on, go around back and push it to the run position, it will stay open and engine will start. It only does it when engine/solenoid is hot. Next time your mower won't restart, look and see if your shut off solenoid is fully opened. I can hear, or not hear, the click of that solenoid when I first turn the key on, before cranking. No solid click means it didn't switch to run position.
Good ideas guys. I'll report back what I come up with.