there is also a rpm control relay located under passenger side floor mat it is secured to lower foot well will say engine rpm this could be at fault. Also spray carb cleaner around cis head mount and fuel injector seals to check for vaccum leaks if leaking rpm of running engine will be affected. The voltage protection relay also plays an important part if it is going bad it will cause the say thing. It is located next to brake booster silver in color with 10 amp fuse