Lionel GP30 Troubles...

The TMCC manual will tell you, and I'm sure that it is available online.

Steven, I'm not sure if this is what you want.

STALL
STALL is a useful setting for LIONEL engines that have AC Pullmor motors. Sometimes
a Velocity Throttle will have to be turned a lot just to get these engines moving. Setting
" STALL" enables you to immediately go from 0 to the level of power your engine requires to
start movement as soon as you operate the Velocity Throttle.
NOTE: Your locomotive may not support STALL functionality. With the locomotive selected,
press the SET button. If the headlight does not begin to flash, STALL functionality is
not supported.
To set STALL, place your engine on a level straight track.
Set STALL
1. Press SET (headlight will flash)
2. Get your engine rolling
3. Turn the Velocity Throttle counter-clockwise until
your engine just stops
4. Press SET ( headlight will stop flashing, engine
will stop)
5. Your engine’s STALL power has been set
6. Press Reset on the Touch Screen
7. Experiment to find the STALL setting that best fi ts
your Pullmor locomotive
Clear STALL Setting
1. Press SET (headlight will flash)
2. Press SET
3. STALL setting is cleared
Note: If necessary, set " STALL" to match starting of Pullmor engines in a lashup with
other engines.

or

Set stall voltage (Engine or
Train – Command only)
To reset stall voltage, press
Set button twice - one
second each time.
- Address Engine or Train
- Throttle up to slow speed
- SET (Engine/Train stops)
- Throttle up to slow speed
- Reduce throttle to just
stop engine
- SET (horn)
Clear stall setting (Engine or
Train)
- Address Engine or Train
- Press SET twice, one
second each time.