I bought a 91 T4R for $500. It looks like a great deal except, I cant get the idle to stay put. I have taken it to a shop and they said that they would probably have to replace the mass airflow sensor. I have not gone back because the mechanic wouldn't believe that it is vane not a mas. Anyway, driving home, I notice that just prior to the idle dropping from acceptable to 200 or 300, there is a vacuum like click coming from the passenger side of the dash. I am not excited about taking the dash apart unless I know what I am looking for. Anyone had a similar problem?