Smoke unit starts when press 9 and then smoke stops shortly after...

Just a thought, does your smoke unit have a thermistor too close to the heat resistor?

dont know what that is or where it would be...what do i look for? it's stock lionel smoke unit in there...

It would be in the actual smoke unit.  There would be a resistor and the thermistor would fairly close to the resistor. I would ask someone else on this forum about how to get access to it. I had a similar experience with an Atlas RS-3 smoke unit.

ok thanks... something to look at...

The actual Lionel product number would be helpful here. If I’m looking at the right one this would be from 2009 (early legacy, so no thermistor)

if the wick is not burnt and moist then I’d suspect the voltage regulator. Unfortunately the Lionel parts site is down, also it was recommended to replace the 6ohm resistor with a 8ohm.

Almost certainly the smoke regulator if it's not just smoke unit maintenance.  I've seen a number of these with the same symptoms, the smoke will start and then just tail off after a few seconds or even minutes.  Replacing the regulator fixes it.

it is from this set...CONRAIL LIONMASTER LEGACY DIESEL FREIGHT SET (SD80 #4120)
SKU: 6-31772

can i ask what is the regulator? and how do i change it?

thanks

Need the parts site for the listing of the actual regulator used in that engine, so until Lionel revives their parts site, I don't have a part number.  Besides, with the parts site down, you can't buy it anyway!

ok thanks...i will wait...

You could pull the smoke unit and make sure it's in good shape, check the wick and the resistor.

John do you know if there was multiple different regulators or did they just have one for steam or diesel? I don’t know if I ever paid that much attention

There's a string of different code versions, and no clear documentation of what they all do.  I know that the one for the early Legacy 10-Wheeler cuts the smoke off when you stop because the 10-wheeler doesn't have smoke at idle and the fan stops.

i removed top of smoke unit and it wasnt burned inside or anything like that.

Well, I'm guessing you have the classic smoke regulator failure issue.

Looks like parts is back...any one point me to right part?

thanks