Hey, congrats on the car buy! I just purchased the same year and model and love it and are going through the same thing you are. Systematically changing everything when I can afford it. However, and people who know more then me please confirm. But hold on buying the new TPS for the stomp test issue.
The 1990 525i, doesn't have a stomp test feature. That didn't become available until the 1992 models. You can find the thread here, I read it from one of the sticky's "mechanical things you should know...". Its the first post under "stomp test procedure"
Again, BMW specialists that are on here, if I'm wrong post, that way I know, he knows, and its confirmed. Hope I help and thanks guys.
Last edited by Hunter8511; 10-04-2012 at 11:04 PM.