Well I have a 91 covertible rx7 with a 90 turbo 2 engine with 45,000 miles on it. Around 1500 rpms it wont stay. It reves up and down over and over. If i rev it up to 2,000 its fine and steady. What things can cause this. Thanks

 

My friends Civic Hatchback does this. His car sounds like it has asthma. He says his idle speed sensor is broken so that could be the problem on your car.

 

Check to see if your TPS is adjusted correctly.

 

I think it's the TPS as well.

 

I have also seen bad BAC and bad AWS do this, but check the TPS first.