Rep Power: 0

I have a 98 civic with a single overhead cam non vtec. when I unplug the map sensor the idle drops to 2000 rpm. I have no check engine light on and can not figure it out.Anyone have any ideas?
thanks

 
Rep Power: 313

4000rpms and no check engine light? Holy crap batman. Check your throttle cable and make sure its not too tight.

 
Rep Power: 235

Does it stay high and not waver much or does it "search" for idle? 2000rpm is still way high, it should be at 700-800rpm for idle. Like tbohar said check the throttle cable. Also check for a vacuum leak. Put a scanner on it anyways, Autozone will do it for free.

 
Rep Power: 0

throttle cable is disconected

 
Rep Power: 217

Checked all your vacuum lines to make sure they're all connected? Although 4000 seems much much higher than I'd expect to see if there was a disconnected line. What's even crazier is no CEL

 
Rep Power: 313

Yea everything other than the throttle cable SHOULD throw a CEL... That being said, make sure the throttle lever is free and not stuck... lube it up if necessary and clean it off with throttle body cleaner... After that I dont know... could be your TPS sensor, but again that should throw a code.