when i bought the 90, it did the same as he described. changed the stat and everything was fine. my 90 was the first car that i really worked on with a computer and it was driving me crazy. a guy told me something a teacher told him when he was in school for auto and it saved my sanity and a lot of time and money. what the teacher told them was to troubleshoot the engine first as that's where most of the problems are. do the computer last.

 

i was doing it backwards and things were getting worse instead of better until i went back to the basics as suggested.