the idle revs up from 700 to approx 1000 for a second or so then returns to normal

this happens every minute or two

have cleaned the throttle body, tried a differnt IAC (ISC) and set the base idle

what is the cause of this and is mostly just EFs that do it or is it all E series?

One thing you may want to check is the power steering pressure switch. My EA had a failed switch and it would idle high at random as well as on trailing throttle (which was interesting to say the least!).

good suggestion, would have never thought of that myself...but yeah that could definately be a possibility...

cheers

keep em coming guys....this is a very common prob that needs solving