I am having some idle problems with my 2nd gen rx7. The idle of the engine stays normal, about 1000-1500 rpm, but only when the engine is some what cool. After driving for a while and the engine has heated the idle of the car drops down to about 500 rpm or lower. It actually sounds like the engine is going to cut off. I have tried adjusting the idle, setting it a higher while the engine is heated and it's fine, but after it cools down and I start it back up the idle shoots up to about 2000-2500 rpm. Then I have to adjust it back down again. I would appreciate any help.