F3 2344 Engine pauses, sometimes stops, over uncoupling track

If you're saying the engine cycles from "forward' to "neutral" when it crosses the uncoupling track, I'd first look to be sure the wire from both middle rail pickup rollers is indeed connected to and supplying power to the "hot" lug on the side of the e-unit which is mounted between the dual motors above the fuel tank area.

A ohmmeter would be handy to check continuity between each roller and the e-unit lug. remember, this wiring is over 60+ years old and may have deteriorated. It is very common for wire insulation to get dry and crack. Also, the wire has to move with the truck and continuos movement, even with stranded wire, can lead to wire breakage with age.

Also, check the drive wheels for "electrical' cleanliness as they also provide the "return" or ground-side of the electrical circuit.

Well, I was going to suggest changing out the UCS track. I have come across old UCS tracks on which one side of the center rail track next to the magnet does not work for some reason.

If you have the problem after switching out the UCS track  then I would check to see if one side of the pick up may need to be bent down some in order to maintain contact on the center rail after crossing the magnet in the UCS track.

Hope this helps,

Richard

If you have the full width early style rollers, the plastic ramps on the ends of the UCS track control rails can lift one roller off the center rail while the other roller is positioned over the magnet area. Thus cutting power and cycling the e-unit to neutral. That is one reason why Lionel tapered the ends of later rollers.

I'll check these out. Thanks!