3930

[D7fever]

3930 diesel, do they all have the intake manifold heater? Also what is the unit with 3 wires that is screwed into the intake tube before the intake manifold?
I only have 3 positions on my ignition switch, book says there are supposed to be 5. Only had this tractor for a few months. Thanks in advance for any answers

 

[Sean in PA]

The intake manifold heater is called the thermostart. It was optional as far as I am aware. If yours doesn't have it, then a 3 position key switch is sufficient. The device you describe on the intake tube is most likely the air restriction sensor which will cause the intake air flow warning light to illuminate when it detects too strong of a vacuum in the intake. If that illuminates you should change or service/clean the air filter depending on whether yours had a dry cartridge type filter(change) or an oil bath filter (service/clean).

 

[D7fever]

Thank you, that solves the mystery. Can one of those thermostats be installed on the tractor easily? Hope it will start in the cold.
I am in MA.

 

[Jim.ME]

Thank you, that solves the mystery. Can one of those thermostats be installed on the tractor easily? Hope it will start in the cold.
I am in MA.

Before installing a thermostart I would install a block or other type coolant heater if the tractor is kept within reach of power. Where power is available a warm engine provides easier starting than glow plugs or thermostarts in my opinion, and is easier on the starter.

 

[Sean in PA]

I agree with Jim on a plug-in heater if the tractor is kept parked near a power source. If not, a thermostart can be added fairly easily. The intake manifold should have a plug in it with a recessed hex head, like a really big allen screw, which you would remove to install the thermostart unit. Then you need to provide fuel and electricity to the thermostart unit. The factory fuel delivery is via a Tee in the return line that takes the excess fuel from the pump and injectors back to the tank. The electrical power is provided by one of those extra positions that you currently do not have on your key switch.

 

[D7fever]

Thanks for the replies, I agree about the block heater, there is one on the tractor, but it is parked in the woods.......... I can hook it to a generator for while and it might heat up. I'll look further into adding a thermostat. Is there an electric fuel pump on the tractor to supply fuel to the thermostat , cant see how it would get fuel otherwise with the engine not running. I think I could hook up switch to make it work otherwise.
Pardon my lack of knowledge on this tractor, been dealing with old Farmalls all my life. I like the 3930 , and the fact that compared to what I had it is a "modern " tractor.

 

[flying belgian]

Thanks for the replies, I agree about the block heater, there is one on the tractor, but it is parked in the woods.......... I can hook it to a generator for while and it might heat up. I'll look further into adding a thermostat. Is there an electric fuel pump on the tractor to supply fuel to the thermostat , cant see how it would get fuel otherwise with the engine not running. I think I could hook up switch to make it work otherwise.
Pardon my lack of knowledge on this tractor, been dealing with old Farmalls all my life. I like the 3930 , and the fact that compared to what I had it is a "modern " tractor.

If your going to drag a generator out to the woods I would drag the knipco out there too. Problem solved.

 

[Fordfarmer]

Thanks for the replies, I agree about the block heater, there is one on the tractor, but it is parked in the woods.......... I can hook it to a generator for while and it might heat up. I'll look further into adding a thermostat. Is there an electric fuel pump on the tractor to supply fuel to the thermostat , cant see how it would get fuel otherwise with the engine not running. I think I could hook up switch to make it work otherwise.
Pardon my lack of knowledge on this tractor, been dealing with old Farmalls all my life. I like the 3930 , and the fact that compared to what I had it is a "modern " tractor.

No electric fuel pump. It only takes a small amount of fuel; teeing off the return line is adequate. My 4600 only has the off/run/start positions on its key switch. I just hold the key past run, but not quite to the start position to activate the thermostart. Hold it ~30 seconds, then crank the engine over. Sometimes, if everything is real quiet, you hear the whoof of the fuel igniting in the intake.

 

[Sean in PA]

Thanks for the replies, I agree about the block heater, there is one on the tractor, but it is parked in the woods.......... I can hook it to a generator for while and it might heat up. I'll look further into adding a thermostat. Is there an electric fuel pump on the tractor to supply fuel to the thermostat , cant see how it would get fuel otherwise with the engine not running. I think I could hook up switch to make it work otherwise.
Pardon my lack of knowledge on this tractor, been dealing with old Farmalls all my life. I like the 3930 , and the fact that compared to what I had it is a "modern " tractor.

As FordFarmer said, and the amount in the line between the tee and the thrrmostart is sufficient to heat up the intake manifold for starting. The tee in the fuel line should be above the thermostart, so it gets fuel fed to it via gravity.

 

[ErnieD]

Take out the paper air filter element (temporarily) and use a propane torch while cranking. Easy peasy. Saw the trick on a John Deere excavator, lot better than ether.

 

[D7fever]

Thank you.