Another 2520 Cold Starting Thread

nuclearsteel · Dec 29, 2012

Got yet 'another' question on starting the 2520 when cold. My tractor was delivered about a week or do ago, and I store it in my attached garage. I don't have the heat on yet, so the temperature is about 40 to 45 degrees F.

I noticed that she struggled a bit today starting up. She fired a bit and sputtered out. I tried it again and it started...as usual you get the "puff" of smoke from the fuel that is not completely burnt.

I was surpirsed by this as I waited for the 'preheat' indicator to go out prior to cranking. I did have the throttle at idle, and turned it to about 50% when I tried the second time. I'm not sure mine has the infamous 'auto high idle" that I have read on here. Doesn't seem to do that....RPMs stay where you put it.

I did some research on here and found a few threads. I'm still unclear if this engine has an intake heater or glow plugs, or both. The manual for this tractor isn't very impressive!

My questions are...

Does whatever preheats, continue to preheat if I leave the key in the "ON" position after the indicator goes off?

Glow Plugs or Intake Heater or Both?

What is the correct throttle position when starting?

Thanks1

Tx Jim · Dec 29, 2012

When the fuel heater isn't illuminated then I think the heater isn't being powered by electricity. I always choose to start a cold engine at idle speed.
HEATER, AIR INTAKE (ENGINE MARKED 3TNV82A-MJK, -MJKE)
GLOW PLUG (ENGINE MARKED 3TNV82A-BMJK)

nuclearsteel · Dec 29, 2012

Now that is good information. Looks like I have the BMJK model, so I have glow plugs. Going to put the Fluke DVM on them and see if they stay on or off with the idiot light.

nuclearsteel · Dec 29, 2012

So for those who always wondered...the heating circuit (glow plugs on my engine) is only active while the 'Glow Plug' light is illuminated on the instrument panel. When the indicator light is "ON" you get 12VDC to the plugs...as soon as the light goes off, the glow plugs do too.

I guess what this means is that no sense in letting the key in the 'ON' position after the 'Glow Plug" light goes off, cause they ain't heating!

Now I can see the wisdom in repeating this cycle....not sure how they affects fuel going into the cylinder? I'm going to assume that the injectors are 'OFF' until the engine cranks?

Hope this helps someone....it makes me feel better! I'm guess that the other item I have indicated in the picture is some type of thermocouple or sensor in the coolant system...the AWG of the wire is too thin for anything but a signal. I'm not buying that the time the glow plugs are on vary at all with temperature. I'm thinking this is just for the overtemperature idiot light. I can't find any other sensors that would check air temp....I looked online at the parts lookup and couldn't find anything either. My conclusion is that the glow plugs work off a timer that is static.

Tx Jim · Dec 29, 2012

nuclearsteel said:
View attachment 295152

Now I can see the wisdom in repeating this cycle....not sure how they affects fuel going into the cylinder? I'm going to assume that the injectors are 'OFF' until the engine cranks?

If fuel system is operating properly no fuel enters engine unless fuel inj pump is furnishing the fuel to the injectors .