Lexus LS400 Has anyone had this problem?

I bought my 1994 Lexus LS400 used from a private party and soon after noticed the tracking light never appeared on the dash when I started the engine. When I checked the manual I noticed the pages re: tracking system were torn out, which made me suspect. Since we have two other cars I drove the Lexus very seldom. I put 7,000 miles on it during the year we owned it, and the car was functioning perfectly. I thoroughly enjoyed driving it and consequently I never gave the tracking system any thought.
My trouble began when I started to go up a hill and pressed down on the accelerator and sensed the car was starting to hesitate. In my opinion it seemed to originate from the drive mechanism and not the engine. I then took the car to the local Toyota dealer who has serviced my other cars. The Service Manager, after diagnosing it, determined the problem was related to the tracking system. He said he fixed the tracking system, but was then unable to start the car. My car has been in the shop for a week now and the Service Manager still can't get the engine running. He's been associated with Toyota since 1976 and it seems surprising to me that a guy with this kind of experience can't get to the bottom of the problem.
Has anyone run into a similar situation and if so, how was it resolved? I would really appreciate any help you can provide.
Thanks