Just something you can check here, and easily if you have an IR thermometer. I had this issue on an old 3000GT I used to own. I was somehow heat-soaking my starter, so after running the car pretty hard, shutting it off, then trying to start it, it wouldn't start easily. I ended up bending a piece of aluminum and mounting it around the starter, and it somewhat helped my issue. I'm not sure if the starter is in the same location on the NA Capri as it is on the Xr2, but it's something you could look into.