No spark on my Audi 100 after stopping at the shops

What is your question?

I have done a coil test and get no reading between the secondary poles ( meant to be .75 to .81 ohms)nor the coil outlet and the secondary pole (meant to be between 10,000 and 11,000 ohms). I find it strange to get no ohm reading at all. It did get a yellow spark once at the shops but I still couldn't start it. Do they fail in stages like this, there have been times lately when it's done this but letting it sit for half an hour cures it and away we go again. Strange!