idle problem???

car idles fine till the cooling fan turn turns on, after the fan stops it drops in the revs and usally stalls or trys to correct it self and will rev upto 1500rpm and drops and stalls, i had the local garage look at it and they tryed plugging a new computer in and it still had the problem, if anyone could help me out it would be great, cheers

my car is a 1988 galant supersaloon , 2.0 sohc injected

Try checking the idle speed motor

seems like my ecu was slow and was running rich, as i had it hooked upto a computer at my local garage,

i replaced the ecu and the air flow meter and it seems to be idling fine now
if this was the problem i do not know, but seems to work fine now, and dosen't chew threw as much petrol and still has good performance