Problem: Train does not emit - most of the time. Sometimes it does, using the same instructions. The train emits, drives to a trackmark, uncouples and returns to the portal.. This simple sequence rarely works. The train may not emit, It may emit but stall after leaving he portal. A few times it will complete dropping the consist at a siding and returning to the portal. Rerun and a variety of odd circumstances seem to occur. Is this my environment or is the Central Portal Control (CPC) faulty?