how do I raise idle speed on myu Audi A4 1996. It cuts out at idle

You don't want to raise the idle. Clean the throttle body and idle control valve of carbon with throttle body cleaner and check for vacuum leaks. Search for "How to" videos on youtube. Do you have a Check engine light on?

well i would say if your audi is cutting out you have some major blockage issues. so do some intal checks first. A. Check the crank case houses and replace them if there is alot of sludge in the lines. B. Change your fuel filter if it has not already been changed as it most likely has alot of deposits in it. C. When you have the thortal body cover off check it for sludge and clean. D. Clean your air intake sensor it is mostly likely full of carbon build up. E. Change the air filter as well if it has not been replaced in over a year or 2. and F. Fun some fuel injector cleaner in your next tank of gas a good high end one not the cheap ones should not cost more then 19$. Once your done all that you should be running at normal idle again but also check the vacuum lines for breaks the plastic houses have a habit of snapping off on the 2.8 L engines it would be the one that goes from the main vacuum hub at the middle back of the engine to the blue double ball vacuum ball on the driver side

is the check engine light on? if it is hook it up to a diagnostic computer and it will tell you what's wrong. I have replaced Mass Air Flow regulators and Coolant temp regulators to take car of cutting out problems on two of my A4s one a 96 the other 97 both 2.8 engines. Both of these fixes are pretty easy. You can buy the parts on line for a fraction of the cost of the dealer!