ATLAS RS-1 TMCC erratic behavior, stops/starts, jerky

Early Atlas RS-1 had a lot of paint on the wheels.  Required a lot of run time/extra cleaning to remove wheel paint.  Also early RS-1 had two center rail pick-up rollers.  Later issue saw (4) pick-ups on the center rail.  My RS-1 was one of the first EOB speed control models, though it wasn't called that at the time.  There should be instruction about setting the speed control, off/on,  etc.   I cleaned the wheels with q-tips and denatured alcohol.  Took a lot of time, did run much better.  Cleaning and oiling the third rail pick-up also important.  EOB a bit different, not a linear acceleration, takes some time to get use to the delayed response to Cab1 dial movement.   IMO, Mike CT. 

I'm having the same issues with my Atlas RS1 ATANZ.  Thanks for sharing your remedy Mike CT!  I'll give it a try.  

That also looks like it could be the tach strip or tach sensor.  Also, the tach sensor has a nasty habit of breaking a wire right at the board, I had a similar situation with one and it was the a broken wire.  When the locomotive would lunge forward, the wire would connect and it would stop, then the wire would disconnect and it would lunge forward again.

Hey Everyone, Thanks for the replies,

I think Gunrunnerjohn is onto something, when I turn EOB speed control off it runs normally - however not a great solution on my layout as the engine really slows on the tight reverse loops. but in either 32 or 128 steps its still jerky and the light flickers just slightly in sync with the jerkiness. I can't seem to see or find any of the connections to the speed sensor since they're buried next to the smoke unit. any other ideas?

I'm also in contact with Bill from Atlas so I'll see if he has any ideas.

Well, you need to actually get to the connections as the most common break is right where they're soldered onto the tach sensor board.  Remove the smoke unit if you can't get to them.

Tack sensor strip, three wire connection.  There is a black, red, and blue wire attached to the bottom of the tach sensor board.  the wires usually break where the solder ends.   Pictured tack strip on a custom Weaver E8 installation, Timko replacement motors.   Atlas RS1 is a difficult model to service, IMO, Mike CT.  

Some early Atlas RS-1's had EOB speed control.    A complete EOB installation guide from the archives.  Click on the underlined phrase to access.   Latter pages detail adjustments with a handheld Cab-1 controller.  Pre-pulse adjustment, and Background pulse adjustment.