Electrical deviced on fuel line

[Dcara]

Does anyone know what this electrical device with the disconnected wires on the fuel line is? A fuel heater maybe? I just bought this Komatsu D31S-16 (1978 model). It runs great but I'd like to know what this device is.

http://i20.photobucket.com/albums/b249/dcara/75-DSCF0652.jpg

Thanks
Doug

 

[gatractorman]

Most likely is a heater, possibly an aux. elec. pump but dont think so. Also there is an aftermarket shutdown system made that kills the engine when low oil psi or high water temp. exists and the fuel solenoid looks alot like that. But never knew of Komatsu using that from the factory and yours does look factory.

 

[atgreene]

I would guess it to be either the low oil shutdown or emergency shutdown, obviously discontinued. Does this machine shut down by key or do you pull a handle?

 

[Dcara]

It shuts down by moving the throttle to the stop position. The key was bypassed when I bought it so I'm not sure if it would have shut down through it. My ford tractor shuts down via choke.

 

[J_J]

It appears to be a fuel shut off solenoid, maybe in case of an accident. They are on a lot of engines to prevent them running after an accident. or roll over, etc.

Does the engine work with the wires off? The solenoid could also be bad, and not working

It might also be a water indicator for the fuel filter, and shuts down the engine when there is water in the fuel.

 

[DieselPower]

It looks like a shut off solenoid to me to. Have you tried applying power to it to see if it does anything?

 

[irvingj]

Yep. Fuel shutoff solenoid. Can't tell how or what activates it, but that's what it is. (At the risk of sounding pragmatic... diesels don't use spark, so the only way to shut 'em off is to stop the fuel flow... hence, a device of some kind to block fuel.)

From experience with refrigeration solenoids in liquid lines, the shape & design of the housing suggests to me that this is what its purpose is. I'd be interested to learn if you find it does anything when power is applied to the leads--

 

[Dcara]

Good ideas. This weekend I'll see if I can find where the wires connect to and measure the voltage to see if I can determine what it takes. I know its a 24V system (2 car batteries in series). I'll also measure across the wires to see if I get a soleniod type reading (5 to 30 ohms maybe).

 

[J_J]

Good ideas. This weekend I'll see if I can find where the wires connect to and measure the voltage to see if I can determine what it takes. I know its a 24V system (2 car batteries in series). I'll also measure across the wires to see if I get a soleniod type reading (5 to 30 ohms maybe).

You could also try this. Remove the line on the output of the solenoid and see if fuel is flowing. Then take some jumpers, and connect to battery, and touch the wires and see if fuel starts or stops. If no change is observed, then the solenoid may be defective, and that is why they disconnected it. I don't think you would have two shut off devices.

 

[tlbuser]

diesels don't use spark, so the only way to shut 'em off is to stop the fuel flow...

If you completely block the air intake, they'll stop running too.


You could PM darinray , he's pretty good with Komatsu stuff.
And you might find something in this thread helpful http://www.tractorbynet.com/forums/construction-equipment/99717-komatsu-d20a-6-a.html

 

[dirtworksequip]

If the machine runs fine without the wires connected..............why mess with it. If it is a fuel selenoid and you put power to it it may get stuck in the wrong position and then you will have to tear into it and fix it to get your machine running again. Leave well enough alone. Curiosity killed the cat. Or in your case the Komatsu!

Sincerely, Dirt