I have a 84 Tbird with a 5.0L CFI engine. When starting the engine, the fast idle runs too fast - around 3500 rpm. And most of the time the fast idle varies from fast to way too fast. Also, the automatic fast idle kickdown doesn't work. I've narrowed down the problem to the control diaphragm that connects to the thermostat. Does anyone know of a parts source for a replacement pulldown control diaphragm for a CFI engine? Thanks!