Idle Control Valve issues
 

Hi all, Hope someone can help with this one? I am in the U.K and just bought a 1998 V70 2.0 litre 10 valve, Automatic, 178,000 miles. I am having a few issues with several things (all linked to Idle Control Valve I assume) On cold start revs are low 650 to 700 R.P.M, If you rev, you get a very rich petrol smoke from exhaust, once warm revs still a little low 750 to 800 R.P.M (normal is 850 R.P.M according to specs) The car never stalls, stops or cuts out though. I was decided to do a service the other day as it was due, the usual things oil, oil filter, air filter, fuel filter, plugs, pollen filter, top up screen wash, power steering fluid, check the quality of auto trans' fluid (still a nice red colour so must have been changed recently). once all this had been done I done the cursory check all round under the bonnet checking all caps again. Then noticed a "lone" (2 pin) cable just "hanging around" near the I.A.C (2 pin) (which had nothing connected) so as someone that has mechanical knowledge thought that they must be related, decided that as this was part of the (mechanical) throttle assembly, it might have something to do with these issues, re-connected it, on starting the engine (which will start fine with this wire connected) the revs instantly go up to 1800 R.P.M then hunt upto 2100 R.P.M then drop back to 1800 R.P.M and constantly continue to do this with a slight misfire during hunting. disconnect and engine will run as above 750-800 R.P.M. Also NO E.M.L is lit, And NO D.T.Cs are stored and nothing shows up on "live data" when the OBDII is connected!!! Average M.P.G seems poor as well at 28.4 M.P.G. So really stuck on this one. Question is will it be just replace I.A.C valve and "jobs a good-un" as they say or is it possible that it is maybe a faulty M.A.F sensor not talking to E.C.U so E.C.U not talking to I.A.C, or something else not sending the right signal and sending "the wrong signal" to I.A.C? I be-grudge taking this car to my local dealer !!! If someone else has had same issues!!:mad: Many thanks in advance:D