So i have a wierd problem that has happened the last two mornings. When i usually start up first thing in the morning when its cold i get the usual high idle with noisier exhaust for around 30/40 seconds. Just recently though, the fast idle has disappeared after 2/3 seconds and the tickover is down at the usual 750/800 rpm. I know this isnt normal and it doesnt sound quite right either, like its almost struggling slightly to keep running.
I have done loads of searching and have come to understand that there is some kind of system to inject either more fuel or air into the engine for the first part of the warm up period to enable the cat to get up to temperature quicker. If this is correct, how is this system controlled? Via some temperature sensor i would guess?
Anyone have any ideas or experienced similar? Car is an otherwise perfectly healthy ED30
