Ridevertical,

Stopping high going up and stopping low coming down is probably electrical. Check the following:

1. Make sure RE relays remain picked all the way in to the floor, to the point your selector runs off the LU or LD sensor.

2. Make sure CFC relay picks up for about 2 seconds after selector runs off the LU or LD sensor.

3. Generator been worked on lately? Possible that the compensating field is in backwards. Swap D1F and D2F wires to the generator on the back of the controller. You should see the situation either get better or get worse.

4. Check to see that the LU and LD sensors drop off the sensor about 1 mark on the dial from floor level. Possible that they selector is remaining on the sensor too long.

5, Does the car make a smooth approach into the floor, up and down, no hesitation six or so inches from the floor?

Just some thoughts