Indeed, your problem may be stemming from other issues. Did you have a recent and decent tune-up? Did you put Redline sythetic oil in the tranny and rear dif? New tranny filter and gasket? Explore the cheaper fixes like fluids and plugs, cap, rotor, wires, etc. I know you must be frustrated at this point and $1000+ in lost coin and your babey still isn't right. My sympathies, brother. May the automotive gods shine brightly on you.

Jim
1992 500E