Locomotive slows down on UCS track sections..Need Help!!

I have several UCS track sections on my loop of track. The loco slows down when going over them. I have to almost have the throttle on full to get the loco moving again. What might be the problem?? Should I replace the UCS sections or is it the track or pins that are bad?? I use a Z to power my postwar trains. The loco I am using is a 2343 Santa Fe F3 AA units. I have no idea what might be wrong. Any help will do. thanks.

Nevermind, I fixed the problem. It turns out there were some bad sections of track, it was not the UCS sections. All is good now. thanks.

Well, i’m no ucs guru, but I would start by checking the pins. I’ve had trouble with pins for 027 track fitting very loosely into the ucs track, especially on the outside rails.

Also, make sure that the magnet is not somehow operating while the train is passing over it. I have a Super-O uncoupler with a real strong magnet. I’ve accidentally operated the uncoupler right when the engine’s roller passed over the magnet, with the result that the magnet ‘caught’ the roller and stopped the train! And since it was wired to track power, the more juice I gave it to get it moving, the stronger the magnet held onto the roller! Then I realized I was leaning on the UCS controller [:I] IIRC, the control rails of the ucs are wired to the electromagnet, so that when the ‘uncouple’ button is pressed, the rails and the magnet both get ‘hot’. If something were to bridge between the center rail and the control rail, it would operate the electromagnet, too. If your engine were over the magnet at the time, you could end up ‘catching’ it like I did. Could your engine’s rollers somehow be touching both rails? Are they the ‘wide’ type? Are they deeply banded or grooved? Maybe they’re sitting low enough that the rivet on the end brushes against the control rail.

I’m just thinking out loud here. Like I said, no expert, but since no one else was responding I thought I’d give you something to read [:)]