I have a '93 Tempo 2.3L w/AT. My problem is that the idle wanders and changes erratically. Sometimes it will be fast and others it will go down below what I would call base idle causing it to "buck". We have cleaned the throttle body and replaced one of the missing bushings in the linkage. If the "base" idle is set at the dealership (some secret process) it seems to be OK for a while but then eventually goes back to it's old habits. HELP !!!!