3720 (2009) Glow Plug Timing

[Acolar]

I have noticed that on my 3520 when I use the preheat function that the engine starts and runs at an elevated RPM for a pre-determined amount of time. Then it drops back to a normal idle RPM.

I have not experimeneted to see if the outside ambient temp is what determines the elevated RPM or if its the use of the preheat function. I should also measure the time of the elevated RPMs to see if its related to ambient temp (colder it is the longer it runs at evelated rpm)

 

[KennedyDiesel]

The elevated idle is temperature based and not related to preheat function.

 

[ME83]

I have noticed that on my 3520 when I use the preheat function that the engine starts and runs at an elevated RPM for a pre-determined amount of time. Then it drops back to a normal idle RPM.

I have not experimeneted to see if the outside ambient temp is what determines the elevated RPM or if its the use of the preheat function. I should also measure the time of the elevated RPMs to see if its related to ambient temp (colder it is the longer it runs at evelated rpm)

My 110tlb also has an intake heater and does the same thing. It does run at the elevated idle longer when it is colder out, and it is louder when it does too. When the temp is in the single digits it will take about a full minute before the idle drops. When it is in the 30's it lasts for 20-30 seconds. My guess is that it works off of intake air temp/density, and has set times for different temps.

The 110 manual says when it is below a certain temp to hold the key in for 15 seconds and when below another temp to hold it for 30 seconds.

 

[Acolar]

Thanks KD

I was going to place a stop watch in the cab and start collecting times based on outside ambient temps - just for kicks.

 

[KennedyDiesel]

I try to use the fast idle as a measure of when not to move the tractor. I try to wait for it to come down before moving or if I do I take it really easy. The combustion knock/timing rattle can get really nasty if you put it under load while advanced like that.

 

[Acolar]

KD

I agree it sounds nasty during the warmup high idle phase.
I also try and wait for the high idle to come down, although I move it slowly out of the garage to keep the smell and smoke outside the building.