TEREX PT 80 Tracked Skid Loader, Won't Shut Off, Then, Won't Start.

[Industrial Toys]

I showed up at a friends to find his loader idling in the yard. Seems it would not shut off.

First, I don't know anything about this loader.

Turning the key, on and off made the engine run at a slightly different note. But looking at the pump, nothing like a fuel solenoid appeared to be moving.

Finally, I had an idea. Increase the throttle, then try. Well that did it.

But then later, we found it it would not start. No clicking, nothing, except the fuel pump running. Lights work.

Checked:

Seat Belt Safety switch
Seat Switch
Fuses
Relays only by wiggling them.

I'm stumped. But then I don't know how this system works. A fuse reads "micro". Is that a computer?

THANKS

 

[Industrial Toys]

I looked into it a bit. Makes even less sense to me now. There is a single, I am guessing INTERNAL fuel solenoid in the injector pump, So, it makes sense, that there is nothing to be seen moving. Sounds almost like it was sticking. If there was a bad connection, the machine should have shut off. And why did the fuel pump continue to run? That should have stopped with the key off, shutting off the machine.

The schematics are on line, but man, are they hard to follow.

 

[thepumpguysc]

The shut off solenoid is screwed into the inj. pump.. just above the steel lines going to the injectors.??
That's either a Bosch VE pump or a Zexel.. U can try to remove it & see if anything is stuck in the plunger..
a slightly modified 15/16 wrench will usually get it out..
Inside is a plunger & a fine spring.. it doesn't take much to hold it off its seat{keep running}
especially if the owner installed an electric fuel supply pump with the wrong psi..

 

[Industrial Toys]

Interesting. Thanks.

I think there is more than one thing going on. You don't even hear the safety relays click when turning the thing on. Also, learned that the seat switch must be closed before the seat belt switch.

At times like this, this machine just sits there like a giant boat anchor to me. All because people are stupid, do dumb things and society with the lawyers help, reward them financially.

 

[Industrial Toys]

Well, just to complete this. The Mechanic showed up, flicked the switch for the aux hydraulic and she started.

My guess. There may or may not have beens an issue with the Seat/Seatbelt switch, which we corrected, but at some point, my friend had activated the Aux Hyd switch, which must have the starting safety circuit going through it.

The (Internal) Fuel solenoid MUST be sticking which caused the machine not to shut off, but why the fuel pump would not shut it off, when the key was shut off, I don't understand.