I can't keep it up!!

…the rev counter that is.

Everytime I use the car it idles more slowly than before.  I turn the Idle screw to speed it up, but the next time I use it, the idle rev's are low again.

Probable cause please anyone?  1982 GTI (1.6).

Cheers,

happens to the best of us

Actually, I've got the same ('82 1600 GTI) and started to experience the same problem over the last week, now idling around 3-400rpm! doesn't stall though

sorry, I'm of no help! but hopefully someone will have an idea to sort both our cars

First obvious thing - is the O ring on the idle screw doing its job of holding the screw in the same place, or is it worn/perished/hardened/gone missing so the screw is able to vibrate and move around?

Secondly, sometimes variable idle is caused by the mixture being poorly set, normally too rich but can be too lean. This makes ignition more difficult and ignition misses occur, which obviously will lower idle speed since there is no power on the power stroke but the other 3 still do the same.

In fact, poor quality ignition can cause idle issues in general anyhow.

picking up a gunson gas tester and timing light next week so will check it out

Good point re idle screw, though I don't think it's that.

I think the mixture keeps becoming too lean.  I've had it professionally set twice in the past 6 months, but I can't afford to keep taking it to the garage and I don't have the skills/tools to do it myself!

Dodgy metering head?