2.1i/LPG DJ Irratic idle or just a normal VW thing?

[Yozza]

Ay up,
I've recently being doing some work on the engine (heads) and got the engine back together. I've had to re-do the timing/idle speed/tappets and it never runs at a constant idle speed, it's more like 800+/-100 rpm rather than. It's always had an irratic idle speed and assumed this is just a VW thing? If it is then I'll stop chasing my tail, if it isn't, is there any other areas I need check? Air leak, etc??? Another thing, the adjustment screw on the AFM doesn't appear to do anything regardless of the number of turns - what's that about?
Cheerz

[kevtherev]

air leaks...yes

[Ian Hulley]

Having now had a Digijet system in hand it appears to have the same/VERY similar idle speed control valve as the Ford Bosch K-Jet system, these were commonly known to give erratic tick-over on high-mileage (100,000+) motors.

Ian

[Yozza]

Thanks for the replies fellas, I'm gonna work on the basis that the idle speed control valve is the irratic one, rather than playing 'find the frickin air leak'.

[Ian Hulley]

Why not ask a chum and borrow a known good one, to eliminate it ?

Ian.