is it bad that my car idles at 2000 rpms its an 88' and also its starting to overheat now after about 15 minutes of driving

 

In my opinion i would be annoyed by an idle that high. Not sure about it being bad for the car. Mess with the idle screw to adjust it

 

i tried to mess with it a little bit but it seems like whatever i do it doesnt change the idle...

 

get a new MAZDA thermostat and see what happens

as for the high idle i suggest cleaning the back end of your butterfly flaps of your T.B. that can prevent it from fully shutting and idle normally.

 

Check your TPS, BAC, thermowax adjustments, and hard idle stop.

 

would a 3rd gen thermo stat fit or no

 

There is a proper idle set procedure in the Haynes or FSM.

The Factory Service Manual can be found in the FAQ For FC thread. It contains all this information and more, and is an essential tool for any sort of service work that needs to be performed on these cars.

Additionally, the Haynes service manual for the 1986 thru 1991 RX-7 (both turbo and NA) can be found at most local auto parts stores or purchased from any good bookstore (ISBN number 1 56392 007 7). It is only about $25 and is a great quick reference for things like this. Not only does it contain most of the information in the FSM condensed into an easy to read format, but it includes full wiring diagrams as well.

These manuals will answer 99% of service related questions for the car and if you intend to do your own repair work, you will need at least one of them. Preferably both, since the FSM is a free download.

Once the idle is set, you will need to determine why the car is overheating. See this page for troubleshooting information:
http://www.aaroncake.net/rx-7/cooling.htm

 

thank you guys very much for all of your help