Make sure your doors not getting locked up with the restrictor and can't open.
I had a tac 32 once that had perpetual shutdowns since installed. Previous company had sent out everyone trying to fix it, customer was convinced they needed a new elevator. The problem? When the teachers used it they'd hold the car doors, doors went into nudging, when the car doors nudged at the bottom floor that hatch door wouldn't self close the last 1/2". One wrap on the spirator and it was fixed. But that car would run all day long with the doors closing normal speed. I guess noone else wanted to take 5 minutes to grab a 6 foot ladder to get in the pit and thoroughly check out the bottom floor door.
