Volvo Repair: fuel injectors, solenoid valves, injector head

Question
hi dear , first thanks for all what you do for us and for the usefull information you offer to us , I have a volvo 940glt model 1992" with a B234F 16-valve engine , my car consuming too much fuel ( about 110km/20litre intown driving ) and I checked all the fuel injection and ignetion components and sensors , the CO comes out from exhaust is about 7% ( too much ) and its idling rough and not stable idling speed ( 650-900 rpm ) , the technecion told me its the fuel injectors , but the solenoid valves of all injectors is working properly , so is it possible that the solenoid valves not closing in the proper speed so it cause too much fuel outlet or is it possible that the injector head get bigger so its spray too much fuel os its just dirty injectors ? and in each possible case what is the solution ? and do the intank injectors cleaner effect well ? , thanks again and sorry for long quesion :)

Answer
the injectors may open and close properly but the spray pattern may not be right either from being clogged or just from getting old.they should have a nice even spray (mist type)pattern not a stream or drip at all.you could try an injector cleaner this can help if they are dirty.