I'm trying to set my Mini up so that it runs properly.
The problem I've currently got is an inconsistent idle! I can set it up fine, nice idle at around 900 RPM and nice mixture (set with a colourtune), at operating temperature.
Then if I drive it the idle might go back to 900, or it might be at 1500 or somewhere in between.
I suspect that there might be air getting in somewhere as the mixture often feels weak when accelerating and I've had to fit quite a rich jet (AAA) to get it near correct (though still too weak when accelerating up hill).
I've fitted 3 different carbs (currently on HIF38), and changed the manifold gasket, but still get the same issue.
It's a 998 with an LCB and Minispares heated inlet (though it's currently unheated).
The timing appears to be spot-on.
A compression test has all cylinders around the same value.
Any ideas? I've had lots of cars with SUs (twin and single), and have always had them running correctly, I'm out of ideas here!
Just had a thought, is it possible that the manifold is leaking into the water heating pipes? I'll have to try sealing them up to see if that makes a difference.