[ischmitz]

William,

sounds you have your plans well sorted out. I actually have gotten a 19-pin socket myself but never ended up installing it. And the reason for me is that I will keep my custom cable with the car. So if I (or a future owner) ever needs to take it to a shop he will also get the cable that connects to the shop's Hammer or PST2.

Accroding to the WSM the mixture adjustment is done with the idle bypass screw on the AFM for cars WITHOUT O2 sensor. There are instructions in the WSM. You need a CO meter and adjust idle to 0.4% - 1.2% before the CAT. Any intake leak will show up and thow CO way off towards smaller numbers (lean).

Others might correct me but it is my understanding the the air bypass screw is used to suplement the total amount of air that gets into the engine through the ICV at idle. So once you change its settings the ICV will shift its average position. In other words you want to center the ICV by properly adjusting the bypass screw. The hammer will show you real-time values for the duty cycle of the ICV. If the screw is mis-adjusted the ICV might max out when trying to stabilize idle.

On cars with O2 sensor the mixture itself is a result of the O2 sensor closed loop regulation. The Motronic calculats the amount of fuel based on the O2 sensor signal. So it is my opinion that you don't really adjust the mixture itself but you adjust an offset to the ICV position so it can do its job properly.

The reason I am saying that is that there is nothing done during the adjustment procedure that would center and disable the ICV. In contrary on the 3.2 you put a jumber into a test port and effectively stop and center the ICV. Then you make adjustments. This is not the case with the 964.

Read the duty cycle of the ICV during idle with the hammer. It should be around 55% - 65%. If it is way off you have false air getting into the engine (leak) or a grossly misadjusted bypass screw.

Cheers,
Ingo