After lunch, diesel tractor won't start

[geoffleach]

Antonio Carraro TRH 9800, 4 cyl Yanmar diesel engine

Spent the am pulling a flail mower. Not even a hick-up. Returned after lunch, it would not turn over. All indicators normal, no sound from the starter solenoid.

Here's what I've looked into so far. Safety interlocks on seat, parking brake, clutch pedal, PTO, direction selector all OK. Battery 100%, air filter cleaned, fuel pump running, fuel 80%, battery connections cleaned and tightened, glo plug heater OK, fuses (including main) checked.

I hot-wired the starter. Turns over OK, but engine does not fire.

This tractor, including the engine, has sensors everywhere. I've verified the safety interlocks, but clearly I'm missing something.

Suggestions, even the wildest, will be appreciated.

 

[ptsg]

Try cycle all the levers. PTO switch and lever, gear and range levers, etc. Maybe one of the safety switches got stuck, thus prevent the tractor from starting.

Since it's an HST tractor, make sure the pedals are in neutral.

 

[thepumpguysc]

It prob. wont fire because it has an electric shut off on the back of the pump.??
Just hot wire it & see if it'll run.
DONT run yourself over..

 

[Avenger]

Does your tractor have an OBD2 port?

 

[geoffleach]

Now wouldn't THAT be nice. Alas, not that I know of.

 

[geoffleach]

Good point. Alas, I've toggled wverything more times that I can count. And the various pedals are in neutral.

 

[k0ua]

Good point. Alas, I've toggled wverything more times that I can count. And the various pedals are in neutral.

Now we have to start getting scientific with it. You need a schematic. It seems you have two problems, engine won't crank and when hot wired tractor won't run. Both are likely related. The first thing I would want to know is why doesn't the engine crank? Well there is likely a starter solenoid, and a starter relay powering that solenoid. Take voltage readings, and find out why one or both have no power when the key is turned to start position. Is there voltage on the input of the key buss? Does the starter relay coil energise? If not why not. How is the starter relay supposed to be energized? How many safety interlocks are there before that coil gets power and ground and energizes? Lots and lots of questions, but the only way to fix it is to use scientific method. Divide and conconquer. Is the problem this way or is the problem that direction? These are the questions you need answers to, and a schematic wiring diagram is a must. You have tried all of the "wiggle this and that", and it ain't fixing it. The engine won't start is because there is likely no voltage or impulse to pull in the stop solenoid for the fuel supply. On my Kioti is is complicated, there is a Pull coil (high current) and a hold coil (very low current) to make this work. the Pull coil is energized by a 1 second pulse from a module on the tractor, . You MUST have a schematic AND a good multimeter and the experience and initiative to tackle this. Or just tow it to the dealer and say "here, fix it.".

 

[geoffleach]

No power to the solenoid. Working backwards.

 

[kthompson]

Look for a wire being pulled off a safety switch by a stick or large weed or such while mowing before you cut it off. Relax and work each safety switch. On one of our ztr mowers the steering levers are back to not fall in the full release of the safety switch.

I have a Kubota CUT tractor that did this, turned out the pto linkage was slightly bent during use that and had thrown the pto lever slightly out of the normal position for safety switch to release. I found it by holding the key in the start position with clutch depressed as required and worked one lever at the time.

 

[k0ua]

No power to the solenoid. Working backwards.

Now find the starter relay that energizes that solenoid. Does its coil have power when key in in start position. Does other side of coil have ground. How many safety switches are in series with this coil? Either hot or or more likely ground. Just making this up as I go along, because I don't have a schematic of any kind.