I'm having a problem with my NH 494-5 and my Flyernel Western Pacific PA's uncoupling between the A's but the couplers are not opening. It appears that there is enough of clearance so they can pull free, almost like the couplers are spread apart. Anybody ever come across this and how did you correct it.........Ted

I take it they differ in height? I had to bend the A unit coupler 'beam' from the truck up a bit so they matched. Have you had an issue with the E unit on these?

No they are the same height, I just don't see how they can uncouple with out them opening. I had no problems with the e unit in the WP......

Are they uncoupling around a radius or on a straight section of track?
I have issues with the pass cars, but they open up.
I had a WP A unit derail and caused a short. The computer chip in the E unit now has a different rate of acceleration. Cannot get it to creep for coupling of cars now. Just wondered if you saw the same thing, seems to happen in all Flyonel A units.

It's happening on the straights, they run fine and they are not opening when this happens....

So one coupler is not riding out and over the top of the other? Sounds like a coupler fishmouth is out of size. Is it at the same spot of the layout that it uncouples every time or is it random any place on the layout? I did have some newer flynel that the coupler wieght/spring were not strong enough. The weight tended to walk up on its own or a AF switch would give it a nudge. See if you can shim the weight down or see if the coupler weight is hitting something on the layout. It doesn't take much of a tap for these things to release. The fix for mine was to replace the couplers or another I shimed the coupler weight so it stayed down.