When running a chip, you should keep the ignition set to stock (6 degrees BTDC), according to Garrett Chips. The chip will take care of advancing the ignition. For stock cams and the eurocam, you should also leave the fuel mixture set to stock (2.5mA) and let the chip provide the extra fuel. With phat cams, I've personally seen power gains on a dyno by going a bit over the stock setting (0-1.5mA). TT cams aren't that big, so you should be okay with the stock fuel setting. If you're getting pinging, you probably have carbon buildup on top of your pistons. Only way to fix that is to take the head off and scrape. If you still have the plug in your fuel distributor, your fuel is probably set to stock. I've never adjusted mine (200K miles), I just put in a chip.
Make sure you have no vacuum leaks. <<I am going to attempt to verify and adjust the mixture on my 90 jetta 16v. It is a cis-e motronic. I am using the info on the following page: http://www.iders.com/alexweb/vwtuning1.html I have a tt chip programmed for the tt cams installed now and my car has slight ping under load. It has always had a slight ping, barely audible, but you can feel the car back off the timing. The new tt chip and cams seems to have made it a little more noticible than my old tt chip. I've already set the timing for 5 degrees advance and that didn't make any difference. Anyone have tips on how to adjust the mixture aside from this page? What is the best way to get access to the adjustment screw? Drill and thread a small screw into the plug then pull it out? Has anyone done this except Alex, who created the help page above? :)>>
