Engine not shutting off

[JASTN70D]

My 2004 TN70DA will not shut down. The problem first started as a delay of maybe a half to a full second were the key would shut off all electronics yet the engine keeps running. This happened maybe 10 times over the last 2 weeks.

Yesterday it would not shutoff at all 3 times and then would 1 time and then again would not. So the problem is intermittent Any ideas?

I assume there is a fuel shutoff that is supposed to take place anyone know how the circuit is designed?

Thanks in advance for any help

 

[kozak]

JASTN70D,

Did a search on net & found the following.

"DIESELING: Causes can range from inferior gas to excessive idle speed. Carbon in the combustion chamber may also cause dieseling.

Your engine run-on could also be a problem with the vacuum system. (leak)

Vic

 

[DK35vince]

John,
There should be an electric shut down seleniod near or on the fuel pump.
Sounds like the selenoid or linkage is sticking ( a little shot of pentrating oil) or binding.
Also check any wire plugs going to the selenoid for good contact/connection.

 

[PineRidge]

John I would bet it'd the fuel solenoid also.

 

[jinman]

John, the fuel shutoff solenoid should be at or very near the fuel injector pump. It has to be able to immediately shut off all fuel, so it may even be built into the injector pump.

There should be one wire coming to the solenoid. It will probably be some form of spade connector terminal. When you shut your tractor off and it continues to run, remove the terminal manually. If the engine stops, the problem is probably in your ignition switch, allowing 12 volts to the solenoid when it should not. I

f the engine keeps running after the connector is removed, the problem is trash or a faulty return spring in the solenoid causing it to fail to disengage. I'd tap gently on the solenoid to see if the engine stops. Either way, you will know whether you need to replace the solenoid or replace the ignition switch. It's gotta be one or the other.

 

[RickB]

There is an outside chance there is an internal problem with the injection pump. There have been problems with recent Bosch pumps used on NH equipment. Just before I left the dealership, we had a LS190.B skidsteer that would not shut down consistently. The solenoid and its power circuit were not at fault. NH was familiar with the symptoms, but at the time (Oct) they did not have a ready solution. I bet by now that injection pump has been sent to a Bosch dealer.

 

[JASTN70D]

Thanks everyone. I am under warranty still but the transport cost is like $250 to the dealer.
It would be nice if it were a simple problem with the solenoid. I will start the trouble shooting and let you know what I find!

 

[schacht]

RE: Solenoid -- I buy hay from a local farmer in Northeast Tennessee who recently finished rebuilding a NH tractor that caught fire with ~ 400 hours on it. He thinks the solenoid overheated and, due to its placement near the fuel tank, caused the blaze. He told me he knew of four or five other NH tractors that had suffered similar fires. One belonged to a neighbor and reportedly ignited when it was not even running.

 

[PineRidge]

Guess that might happen with gasoline but with diesel I dunno......

 

[Robert_in_NY]

What model New Holland tractors?