Last week I bought Carisma 1.8 GDI
In user manual there's something about GDI-ECO light showing best fuel-economy driving. It never worked in my car. Also there's small problem with idling - sometimes rpms are going almost to 0. Usually engine recovers to normal rpm (~600), but sometimes not.
Anyone got similar problems? What should I check? How bad does it look?

don't know what the light is you're on about - there's an ECO light on my one's air con, but sounds like you're on about something different.

mine also has the revs drop right down on occasion, sometimes it'll stall the engine, other times not.

i don't know what causes it, but it is reduced by using premium unleaded rather than the regular. Also stick in a dose of injector cleaner for good measure. If it's any help, mine hasn't got any worse after a year's driving...

i've read the injectors are quite prone to getting coked up, but cleaning them costs about £500.

The GDI light is suppossed to come on to show that you are driving economically, my carisma idles around 600 rpm and it took me a long while to get used to low revs and kept stalling it when I first got it. It works similar to an old polo a friend of mine had which worked of engine vacuum I think

Jerry Ive got a '99 Spacestar 1.8 GDI and although my eco light worked I had poor running, uneven idling, poor fuel economy etc. It turned out to be the non-franchised garage my parents (who were the previous owners) used did not use the correct engine oil and this caused the fuel throttle body to sludge up. Dont ask me what the throttle body and the oil have got to do :57: with each other. Apparently if the correct oil (high quality) is not used then the throttle body needs cleaning out or as a final resort replacing (big bucks!). The work cost me £180 and the car now runs better and gives far better fuel economy! hope this helps!! Rob