i have a 98 EK with a 98 GSR motor swapped in. my question is that when its in the morning the car starts up fine and idle fines. when i start driving its still good. the problem is when i push in the clutch to throw it in neutral to get ready to stop, the car stays at a high idle. when i come to a complete stop it then drops back down to a nice idle. what do you think the problem can be

 

If the engine is still cold, it will do that until it is warmed up.

It can possibly be a bad idle air control valve that needs cleaning or replacement. Or maybe the idle needs to be adjusted. Other things can be a sticky/dirty throttle body, minor vacuum leak.

 

Yeah thanks for the help im gonna take the IACV off today and clean it and see what happens