Fiesta mk 4 Idle problem - mr b quality
I have an S reg Fiesta Ghia x with a zetec 1.4s engine, started to notice that when I approached junction at low revs the engine would sometimes stall this will occasionally happen when I am in sittting in traffic and the engine is idling it will rev fine for a while and then suddenly revs will drop and either stall or almost stall and then revs go back to a normal level, there is no set pattern either for this sometimes it does it and sometimes not. Car starts fine every time and runs fine in higher revs just seems to have a problem idling totally confused about the cause of this any ideas much appreciated !!.
Fiesta mk 4 Idle problem - Dynamic Dave

Not sure if this'll help or not?

www.honestjohn.co.uk/forum/post/index.htm?t=18068