Hmmmmm
So on the way to have the car MOTd, the idle speed was 750 until the engine was truly warm and the cooling fan finally came on... Small throttle openings (driving in heavy traffic) seem to be a big provoker of increased idle speed?
Prior to driving to the garage, I had tightened-up the 4 jubilee clips relating to the Idle Control Valve and the air pipe between the MAF and the throttle body - none were slack but I was able to nudge them up a little
It's snowing now so I haven't tried the two tricks that you have all suggested, but I will look into these
Meantime, it has been suggested that the injection system will increase fuel to the engine in response to load on the alternator and so when the cooling fan kicks in, the injection system responds accordingly. The only problem is, that when the cooling fan switches off, the revs don't drop. In my mind there is a connection with engine temperature and the idle speed - that would point to a fault with the temperature sender and/or how the ECU is interpreting info coming to it...
My only reservation about the FPR possibility is that the car is fine to drive (consistent at least) and the fuel consumption is in reasonable bounds
I'll get there in the end!
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