4000 cold start gadget

[Bill Allis]

68 Ford 4000, 3 cyl diesel has the cold start gadget on the intake manifold with the fuel line and electrical connection. Just how does it work and how do I service it. Can't find a name for it or anything about it in the service manual I have. I am sure it is supposed to work off the ignition/start switch, but I don't find a wiring diagram that explains it.

 

[JMOR]

(quoted from post at 10:04:40 10/14/13) 68 Ford 4000, 3 cyl diesel has the cold start gadget on the intake manifold with the fuel line and electrical connection. Just how does it work and how do I service it. Can't find a name for it or anything about it in the service manual I have. I am sure it is supposed to work off the ignition/start switch, but I don't find a wiring diagram that explains it.

ounds like cold start ether injector.

 

[old]

Can not say for sure but if it in in the manifold and has a single wire going to it then it is a manifold heater and you hold the switch on most backward from the start to heat it up wait 30 seconds holding it that way and then try to start. If it has a can of starting fluid on it some place then it has either start. Do not know that tractor well enough to say much other then what I have said

 

[Sean in PA]

That model had what was called the automatic thermostart. It uses electricity to heat up an element inside the intake manifold, and it dumps some fuel in there as well, and the fuel catches on fire when it contacts the hot element. The thermostart was standard quipment on diesel models with the Selec-O-Speed ttranamission and as an option on the models with manual transmissions. There was also an ether spray primer available for models with the manual transmissions, but that was a can of ether that was below the dashboard in front of the shifters with a button to spray ether into the intake and that did not have any electrical wiring going to the intake manifold.. What you are describing sounds like the thermostart.

For the models with the thermostart, the key switch should have 5 positions. The middle position with the key slot straight up-and-down is the "Off" position, and the switch should not be providing power to anything in that position. One click to the right from the "Off" position is the normal "Run" position, and one more position to the right from that is the normal spring loaded "Start" position. One click to the left from the "Off" position is the "Heat" position, and one more position to the left of that is the "Heat Start" position. Both the "Heat" and "Heat Start" positions are spring loaded.

In warm weather, you start it normally by turning it all the way to the right to the spring loaded "Start" position. When it starts, you release the key and it springs back to the "Run" position, which supplies power to the gauges and idiot lights.

In cold weather turn the key one click to the left from the off position to the "Heat" position and hold it there for 30 seconds, and the Thermostart unit should dump some fuel into the intake manifold and light it on fire. After 30 seconds, turn the key one more position to the left, to the "Heat Start" position and hold it there until the engine starts. When it starts, release the key and it will spring back all the way to the "Off" position. Then, if you want the gauges and idiot lights to function you need to manually move the key one click to the right to the "Run" position.

 

[Tequila]

I have the same tractor, the manifold heater operates off a key switch terminal. Should be a wire from ignition switch to the manifold heat unit. To operate turn key to on position,(idiot lights on), then turn key slightly farther, (idiot lights out) and hold between on position and starter position for 20 to 30 seconds to heat intake air and fuel mixture. Then turn key to activate starter. Either works or it don't. No service needed. You could check amps pulled when on to see if it works. I have never removed mine, probably pretty stuck in the manifold.

 

[David G]

Thermostart heater, the others nailed it.

 

[mhb@ufe]

The direction the key turns to activate the thermostart is dependent on which switch you have. The original switch had two spring loaded positions to the left as Sean described and the replacement switch turned to the right as Tequila described. There was a service bulletin on the new switch with a wiring diagram as the terminals are different on the new replacement switch. If the switch was replaced and not wired properly the thermostart will not work.

Mark

 

[Texasmark1]

Trying to remember the models I had. I had a 4600D and currently have a 3000D and a 2000D 4 cyl with glow plugs, and a 4 cyl 4000 and a MF 35 with it with the Perkins 3 cyl diesel.

One had the key switch as mentioned. Another had a separate push button for the thermostart. The MF had the key turn to the left for thermostart where starting was to the right.

On the push button tractor you turn the key on and hold the button in the same manner the key turn system worked.

The diesel drops falling across the hot coil catch fire as mentioned and the sucking intake valves suck these blobs of burning diesel into the combustion chamber and light it off.

Service is to ensure that the coil will glow red and that the glowing red coil will open the fuel valve and allow diesel from a separate line from the tank to dribble onto it and catch fire.

If you don't know where it is look on the inside of the intake manifold just to the rear of where the hose connects from the oil bath air cleaner.

Mark

 

[Jr in nwmo]

A new heater will cost you about 25 bucks,i have one on my 2000 and 5000.I have been told not to use ether when using the heater it will blow the manifold off,just thought i would pass that along to you.

 

[Bill Allis]

Automatic thermostart, OK I will start a search for
that. I had to replace the switch, it was so badly
worn that the key would fall out. Replacement switch
was different from what was in it and I am sure I
don't have the wires right, although it does run the
starter. Anybody got a wiring diagram?

Thanks,

Bill

 

[Sean in PA]

I&T F0-31 manual has the schematic. Sorry I don't have access to a scanner right now. Basically the thermostart is connected to its own terminal on the back of the key switch, but if yours is a replacement key switch that doesn't match the original then it probably don't have a position on the switch to run the thermostart either. You could install a "normally open" spring loaded push button type of switch that you could then use to power the thermostart, or you could pop for a replacement key switch that has the extra thermostart position and terminal. It looks like the original part number for the key switch with the heat start has been superseded by part number 82849085, which is about $30.00 on line or from any New Hollland dealer.

 

[mhb@ufe]

The new switch does have the connection and position for the thermostart. When turning the key to the right there are two spring loaded positions. The first spring loaded position is for the thermostart and the second spring loaded position is for start and thermostart.

Mark

 

[Sean in PA]

(quoted from post at 16:03:27 10/15/13) The new switch does have the connection and position for the thermostart. When turning the key to the right there are two spring loaded positions. The first spring loaded position is for the thermostart and the second spring loaded position is for start and thermostart.

Mark

He didn't say whether he replaced the original switch with the proper replacement, or whether he had just bought a generic key switch, or even if he had purchased the proper replacement switch for the same model tractor without the thermostart. All that he said was that he replaced the switch and that the terminals didn't match the old one.