Hi I'm new to this but hope someone can help? I have a 1998 escort SI 1.6 zetec with eratic tickover when cold, on initial start up the revs go upto around 1500 rpm which is ok initially but once you start driving it starts to hessitate and feels like it wants to cut out, after 5 to 10 minutes it appears to run fine. I have changed oil to 5 w 30 due to the known concern with 'sticky valves' slight improvement but still there, new plugs and leads fitted after finding the 'black lines' down the ivory part of no;3 spark plug. I have some suspisions for either EGR valve or ISCV but don't know how to confirm, Hope someone can help. Many thanks.

first thing would be to clean the idle controlle valve with carb cleaner if still the same could be a temp sensor gone causing wrong fueling when cold