weird idle

So just recently the golf has been idling strange.

Its fine one day then not the next.

My engine is the 1.8 8v DX

Ive herd that the switch under the throttle body can cause this

Ami

Got same probs. This is my list of checks so far !
Fuel pressures
Cold start valve-cold=ok
Cold start valve-hot=ok
Checked compression
Checked Aux Air Valve
Checked fuel pump flow
CO mixture adjusted to 2.2 @ 950rpm
Checked injectors
Checked timing=ok
Airleak check=ok

I think mines now got to be the distributor after all these checks, getting one refurbed by CrazyQuiffs.

Also worth reading, the 'Fuel Injection' under -Technical link in left margin<<<

Good Luck, hope this helps.

will give it a go thanx for the info