A useful analytical tool is to get the car well up to temp (say after a run) and disconnect the electrical plug from the IACV. Check what the car is idling at. It should be 850 ish. If it's markedly different, then, when connected, the IACV will be constantly working to try to bring it to that figure.
A sticking high idle speed can be down to a high base idle setting. It can also be that the accelerator cable is frayed and sticking in its sheath. So check the cable is moving smoothly and allowing the throttle body to close properly.
If the base idle is too low you can get hunting. ie the revs drop low and suddenly pick up and then drop again. In other words the IACV is hunting for the right idle speed. Usually you get a lot of stalling.
So I fuelled up today for the second time since I picked her up, two weeks ago this Friday, and I am getting an average of 32.6.....I am really pleased with that.....can you experts tell me if that is good, bad or average??
How are you recording the consumption?
I use www.fuelly.com , my F is at https://www.fuelly.com/car/mg/mgf/1999/talkingcars/131476
Home to black Alfa Romeo 159 3.2 V6 Q4 ,green MGF VVC andred MG Maestro T16.
Average of 36.8mph for my 1998 1.8VVC & I have a heavy foot. Well, once you change the air filter & put in a 52 mm throttle body you want to hear that noise don't you?
This isn't a dress rehearsal, this is LIFE, enjoy!!
It's possible, in which case it would cost the earth. £400 plus for a new one. However, it may just be dual tail pipe finishers which can be added to any dual piped exhaust. So, just adding a bling finish to a cheaper exhaust with quad tail pipe finishers might be a better option for you.