My new train engine will stop and start and just plane fall off the track at random.The track is not nailed down .The track is an e-z track system I got it in the Empire Builder set. Any help would be helpful.

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http://www.bachmanntrains.com/home-usa/board/index.php/topic,6776.0.html

Follow his instructions for cleaning.
Clean your loco, tender, and all rolling stock wheels.

After you have finished with that, then run your finger over all your rail joints. You should not feel any "steps". If you do, then check to be sure the rail is inserted properly into the rail joiners and not riding on top of them.

Follow with a check of your wheel gauge, loco, tender, and all rolling stock.

Finally check your track gauge.

Good luck

NOT A BAD IDEA IS TO CLEAN THE TRACK TOO. ESPECIALLY IN HUMID AREA ( I LIVE IN FLORIDA) THIS IS A PROBLEM. FOR FEW BUGS YOU CAN GET A CLEANING STONE OR CLEANING SOLUTION, FOR ABOUT $50 YOU CAN GET ATLAS MOTORIZED CLEANING CAR. IF YOU DO NOT USE TRACK OFTEN (LETS SAY YOU PUTTING IT AWAY FOR FEW WEEKS) IT IS MORE THAN RECOMENDED. GOOD HABIT BEFORE EVEN THINKING ABOUT DCC....
JACK