If I understand what your saying...the starter is sometimes engaging and sometimes not. Do you mean that you hear the starter spinning and not grabbing? If that is what you are saying...then it could be bad news. Is it making like a grinding noise? If so, you might have a problem with rounded teeth on the flywheel. I had the same problem, it would catch sometimes...and then start right up and run fine. Then other times, you need 3 or 4 tries for it to grab. Eventually nothing, and then its pull the transmission to replace the flywheel. You did mention the tranny was out of the car...I would think they would have seen the flywheel if it was bad, so maybe Im just guessing.It might be something to look at if the symptoms are a grinding noise and the starter is spinning though.
