Mostly maintence advice:
Before you mess with the idle, timing, CO mixture, make sure or try:
Your injector o-rings/shrouds are good, you can tell by spraying some carb cleaner around the base and if theres a vaccum leak the idle will fluxuate briefly. Or if you grab the injector line and wiggle it, good o rings will be firm, bad ones will wiggle.
Follow all vaccum lines to their end make sure theres no leaks.
Your broken dip stick funnel is a vaccum leak.
Go thruogh all eletrical connections spray them with Wurth Contact OL, its a contact cleaner/enhancer.
Clean your grounds with some emery cloth, and put dieletric grease on them.
Make sure your Tune up stuff has been done within the last ~30,000 Miles Bosch plugs, fuel filter, decent wires oem bosch are the best IMO, Mann air filters are good, or make sure you clean your K&N when its full of crap.
Some dieletric grease around the plug wire boots makes a better contact and lets you take them off easily. o2 sensor should be done every~ 60,000 miles.
Most 16Vs run noticably better with a good grade of Gasoline.
A bottle of fuel system cleaner ie Techron, by Chevron will do wonders for dirty injectors, and excessive carbon build up.
Get a Bently Manual