8v 1990 Gti has a rough idle. It get better after about 2500 rpm and runs smoothly if you disconnect the wiring to the throttle microswitch although the rpm does increase. As soon as you reconnect the microswitch the rpm drop and it runs rough again. The blue temp sensor has recently been replaced but the issue existed before I changed it. If you unplug the ICV it makes no difference, it runs rough with it connected or disconnected. Some ideas needed please.
Have you not answered your own question regarding the microswitch/its wiring or possibly its setup - can you start there first as I know over time the switches and or the wiring can go for a burton.
