Hey everyone,

This is my first post here. I recently required my grandfathers ‘84 Mustang GT Convertible. It runs but has issues. The main issue I’m having is a surge when I put it in park. For example, I start it, everything seems fine. I drive it, everything seems fine. However, when I get back to the house and put it in park, the engine surges to about 1500rpm, stays there and will not come down. Has anyone else had this issue or know how to fix it?