weird idle

[vtracer20]

Hey guys, so i took the car for a drive today for about 20 miles. After the car got warmed up and when i would stop or have the clutch disengaged my idle would go up and down. Any suggestions to what this is? I've had the same problem with my accord and i think it was air in the coolant would that be the same thing? It goes up to 1.5k and back down to normal 1k idle. It started to do this after i reset the ecu this afternoon. Thanks

 

[johnk]

It's called idle surge if you do a search you will find tons of stuff on it there are quite a few causes for it. All the ones I know have to do with electronics in the throttle body.

Or another possiblity is that it could be as simple as setting the base idle to the right RPM. If the BISS is open too far when the computer goes into the closed loop for the idle it's gonna rev up from having too much from the BISS and then hit a fuel cut at 1500 rpms and dump down then repeat itself.