[charlieM]

I think, my car have idle control valve. This is how it looks like. http://www.ebay.co.uk/itm/Rover-200-400 ... 43a8a2025b
I swap IACV twice. And clean it with carbonator cleaner. Try to reset it, whit your process but car still stalls.

Are all the spark plugs the right colour?

which colour is right? All 4 spark plugs is black.

Other symptoms? Hm, if I drive at 2500-5000rpm engine revs falls ( I dont know the right english word for this) realy slow, when I press clutch. But if I press clutch at 1500-2000rpm, rev falls quick and there is big chance that car will stall. At idle, car runs very well. Always at 800-900rpm. When I use air condition, engine loss a lot of power and torque and stalls.

sorry for bad english

[E_T_V]

After a good run the spark plugs should be grey/brown not black so something isn't right.

I'd look at the inlet manifold gasket as if you have a plastic inlet manifold this was a common problem.

You could also try unplugging the lambda sensor to see if this makes any difference.

[charlieM]

Hi

Sorry for no replay, I was on holidays. I check spark plugs one more time, and they are grey/brown. I also replace inlet manifold gasket, but problem is still there. Also try with unplugging lambda, but still stalls. Are there any critical vacuum pipes, I think I check them all, and they are all good. I spray on vacuum pipes with carburetor cleaner spray, but there is not engine rev change.