Solving idling problems Part 2

Well, the final diagnosis was that one of the spark plug was broken and shot current to fuel ignition which couldn't return fuel as it should. The reasons for these was that I assembled the fuel return part wrongly and because the car's previous owner had tightened the spark plugs way too tight and therefore one had a crack.
So there was extra fuel on ignition which caught an unfortunate spark from the spark plug. I had previously tried to check the plugs but they were too tight to open. Mechanic told me that he used one meter-length extension arm to loosen the plugs.
Faulty spark plug was the main reason for a twitchy ride. I also replaced the broken vacuum advance unit.

Fiat Uno vacuum advance unit. New one on the right...

But after all this, Fiat still experienced idling problems. The culprit seems to be sometimes working idle control unit. Problem is now evaded by adjusting the idle speed a bit higher than normal. That's done by limiting the movement area of the ignition end of the throttle cable. New replacement idle control unit costs about 100 euros and there are plans to replace it as well.

But after these little experiences this Fiat Uno is working actually quite well! Here's the pic where you can see the current state of the car. Well, it's been washed after this picture was taken.

Fiat Uno 1.1. i.e. S