Zhriver

Hi everyone.
I recently purchased a cheap Audi 80 1.8S automatic.
It's from 89 and only had 140K km on it and otherwise in good shape.

However it idles high, the idle will range from 1200rpm to 2000.

On rare occasions it will start throttling up and down on its own, from idle 1200 to around 2500, it stops doing this if I keep it above 4000rpm for a period.

I haven't had a computer on it yet, since none of my mechanics have one with an adapter that fits it. Also a single visit to a shop would probably run me more than what I paid for the car.

Thanks in advance everyone.

Rusty Spokes

Sounds like an air leak somewhere in or about the intake manifold. Check your vacuum lines, rubber fittings and intake gaskets. You can use some Carb Cleaner as spray it on suspect locations and see if the idle changes.

jonas321

Also don't overlook the rubber o-ring in the idle adjust screw. These notoriously get hard, crack, disintegrate and can cause a big unmetered air leak.

What kind of fuel injection came on that 1.8s? CIS-e? If so then I'm pretty sure there is an ISV to check too.

Zhriver

Hi again everyone, thanks for the tips. I'm currently going over the things you mentioned. I'll be back once I know more.
Cheers.