# 5205 fuel pump sensor



## GFC Firefighter (Jul 15, 2010)

I fought until the interweb saved me. Found out why my pump wasnt sending diesel to the injectors...THE STUPID COLD START SENSOR! Well we unplugged it because the fuse was blown and kept blowing fuses. The tractor fired right up!!

Will it be ok to run it unplugged? I know what it is for but didnt know how it will affect these new model tractors..im so old school.

Thanks!


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## sixbales (May 18, 2011)

Howdy GFC Firefighter,

My neighbor's JD tractor had this same problem several years ago. 

The cold start sensor adjusts the injection pump timing when the engine is cold (below 50 degrees centigrade/122 Fahrenheit) for ease of starting. As long as it will start without the cold start sensor, you should be ok. I would fix it soon.

One thing...DO NOT use ether/starting fluid to cold start your engine.


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## Fedup (Feb 25, 2014)

It's my understanding that the solenoid involved here is not for cold starting at all. It is merely an emissions trick to advance the pump timing by a few degrees in hopes to reduce emissions while the engine warms up. Some manufacturers use a temp sensor, some use timers. Deere sensors are well known for grounding internally, blowing fuses and causing problems. If it were mine, I would simply eliminate the wires to and from the sensor, and simply forget about it. The tractor will never know the difference.


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