My cordia really behaves erratically when I use the aircon. It’s generally ok when I don't use it but does do the same occasionally without aircon on.

Symptoms
- it loses power and when trying to accelerate and the turbo needle indicates the turbo is kicking in too early (no power when this happens)
- it bunny hops quite bad (cars do keep clear of me at this time)
- when I pull over (or at traffic lights stop) the engine hunts in revs until it settles at idle just below 1000 rpm.
- it runs rich until it settles down in revs
- now its summer its damn hot without running the aircon!!

Well i know on the carburetor cordia's, there is a little solinoid that ups the idle when you turn on the aircon. there would be somthing similar on the TBI cordia's.
Could it be this is playing up/jumping all over the place? Causing your erratic idle etc etc.

Sounds like your idle speed controller which as far as i know is supposed to compensate revs when aircon is on. You need to reset your tps and isc. The procedure is here somewhere.

I haven't had aircon in my car for 10 years. Window down and 60 is as good as it gets.

The turbo cordia uses the ISC to control air con.........the ECU picks up load when turned on, it's normal to have NO power as it takes this to drive the compressor.........what you are experiencing is the system trying to achieve its set value, hunting idle is normal depending on the aircon cycle.

thanks - will have a look at TPS and ISC