*SOLVED* - Blacktop 20V High Idle

[70XIN]

Hey guys,

I have a blacktop 20V in an AE86. It has a stock ECU. It's idling at about 2000rpm 'cold start', and 1500 at 'normal driving'.

I have cleaned the ISC valve.

When i remove the ISC valve from the engine and block off the 'idle tube' going up behind the head with my finger, the car idles perfectly at 800-900rpm. I have inspected every vacuum line, and i can't find any leaks.

With the ISC valve removed, and that tube blocked off, shouldn't the car stall? Should the ITB's be sucking in air at idle? Could the vacuum "thingy" that sits under the ITB's be screwing with things?

Love,
Seamus