My 1993 RX7 idles at 1250 RPM after the engine warms up; then it fluctuates rythmicly between 1250 and 1500 RPM. When I turn on the parking or head lignts, the engine revs to 2000 RPM and stays there.

Not sure what to adjust. Have tried idle adjustment screw, but seems to have no effect.

Any suggestions???

Thanks, Lee Steelman

 

My car does the same thing. Do a search, you should find a lot of information. I think I've narrowed it down to a leaking lower intake manifold gasket. Unfortunately, the turbos have to come off to replace this.

Paul