Cold start high idle, the doesn't drop

[RuppyT]

Morning all,
As stated I am suffering from a common problem by the sounds of it.
I have a 1992 GT2 carved engine. Recently bought the car with a high cold start idle (car was warm when I bought it).
Usually revs to 3k then drops off, which I find high even in these colder conditions... But today on my 12 mile commute to work, the revs didn't drop off and the revs raised to 4k rpm. The car ran on slightly after I turned it off, but I'm sure this is the rich mixture?
Should I be looking at a new waxstat? Or are there any tweaks I can do to the carb to get it to run correctly?
I'm located in Abingdon, Oxfordshire if anyone could help it would be ace!
Thanks in advance

[scirockirb]

Try this first mate, I found it useful to get my head round it... Not that I've solved mine yet!

www.golfgtiforum.co.uk/index.php?topic=18871.0

[scirockirb]

Just spoken to a carb specialist about my problems and told him your symptoms while I had him on the phone. He thinks almost certainly you've got a vacuum leak from the back. Hope this helps.

Kirby

[Little_bro]

Faulty waxstat and sticking auto choke are the two most common causes for high idle. Vacuum problems are also common with age and its a good idea to change the rubber base gasket. A good sign of a vacuum problem is usually white or coffee colour to the oil on the inside of the oil cap. Or if you can get the car to idle normal-ish when hot it should rev erratically. Hope that helps

[RuppyT]

Thanks for the replies guys!
I restored the carburetor last week by a mate, as it was a multitude of problems! Had the VAC hoses replaced and a new radiator/ coolant replaced too. Seems to have solved the heating up issue. Also had my buddy lube up the throttle cable, as i was having issues with the throttle sticking on whilst on the cold-start.

Car is an absolute dream to drive now, very economical too :)

Pierburg's are great when they run right!