It is an 85 1.9. I recently changed the throttle body from a late type, to
the early 2 switch type. I used the origional early throttle body vaccum
hose set up. The early throttle body has 2 vaccum ports, The late body uses
a vaccum take off from the fuel regulator/air distributor. Could this be
the issue? Could it be the idle stazbilizer?

I bypassed the stabilizer, and got a very bad idle. Hooked it back up. I
see the Bently says that when a VW special tool(or equilivant) is hooked to
the stabilizer,and idle drops below 940 rpm, some test for vaccum advance
functioning is preformed. Could it be the advance mechinism?

The water temp 2 sensor is ok. I mesured the ohms to a particular tempature
and it is good.

The O2 sensor in brand new. However the wire may have a fault.I need to
check it out with a meter, better. Wiggeling the wire got better
preformance and gas mileage. I was 13mpg last week. Paying attention to the
connection here improved this.

The  AFM has the tantlum capacitor and ground wire.

I tried ignition timing several different settings without too much
difference.

Idle is ok when just started with idle set at 925rpms.It is when I drive
when cold,the idle sputters at a stop light till warmed up.