Lionel JLC GG-1's that have not been run for a while . . . . . ?

Sorry to hear about your woes Scrappy

You need to get them out and run them. All my locos run pretty poorly for a while after I haven't run them in a long time. The way they run and how badly really is a mystery to me as its not always the same. Most of the time they run jerky or stall out a lot. I have seen sounds work intermittently and the rollers usually spark for a while. Your Penn Central, unfortunately, sounds as though it will need some internal inspection and repair as it seems like the magic smoke has been let out of the boards

In addition to Matt's suggestions, you might try reprogramming some of the TMCC engines.  Here is a link to instructions.

I would definitely try it on the unit that has horn but no sound.

 Jerkiness is most likely dirty or oxidized wheels and rollers.  Cleaning and/or running them a while should fix them.

if you are using a legacy controller, switching from TMCC mode to Cab 1 mode may fix the unit that is running too slowly.  I have had this issue with several TMCC engines.  Otherwise, it may need to be lubed and run in a bit.  Also check that both motors are running.

Much as I like our modern model trains, postwar Lionel held up much better on the shelf.

Bob

Thanks' Bob, that info can really come in handy someday.

Much like the care of anything mechanical, a pre-storage tune-up will help insure a good runner when next called upon.  If only I took my own advise.  I hope to someday set up a schedule where all equipment gets regular maintenance.  Synthetic lubricants tend to remain a lubricant, whereas Dino juice can solidify from age and heat.

Bruce