I have a rx-7 fc 13-b that has a misfiring issue.
the car starts to misfire at over 1500rpm and gets back to normal at very high revs.
Please respond with some tips or tell whatsbthe problem to fix my car.

 

I'd just be starting with the normal stuff, spark and fuel. Try changing plugs first and see if that helps.

 

How about responding with some details such as engine series, modifications, history, maintenance records, etc. before expecting the mind readers to provide any sort of answer beyond normal maintenance practices...