Thank you to all who have responded. A little more information;
Most problems are with PS3 engines but the PS2 engines are fully charged
There are no other engines or lighted cars on powered track
I only have one TIU connected and powered
The track is clean
I have not checked the signal strength on all 300 feet of mainline but I do get 10 an the area i use to load engines
Update: I have a TIU purchased in 2002 that lost fixed channel one so I found another used one about 2013 and had it upgraded to 6.0. I was using the upgrade model when all these issues began to show up. Last night, I re-installed the older unit using the three good channels. I have been able to add four of the problem engines but the remote will still not find those engines and another PS3 engine (Southern 44 ton) now seems to not want to be found.
I have read here that the latest TIU's seem to function better. I have been looking for newer model since Mike announced he was closing the company but have come up empty handed!
Will there ever be another run of these TIU's?
Don
