[gregory914]

The other items to check on too; intrcooler, fuel injectors, fuel pressure, pump, regulator, ignition timing, spark plugs heat range, main CPU, oil and water connections to and from turbo and one thing I remember when I bought my 89 turbo is that there is no vacuum, the intake manifold becomes pressurized under boost and there goes your vacuum.They put some kind of a pump on my car when the dealer added the factory cruise control. You may want to check that out along with the vacuum lines to the power brake booster too.
It may be better to sell the car and buy a turbo 740 or 940. You may end up shortening the life expectancy of your motor because you'll love putting your foot in to it once you feel the turbos KICK!