'84 240Ti idle varies

Hello,

I could not get my '84 240Ti to pass the emissions test today because
it idles too fast - around 1400 RPM.

When cold, it idles around 850 RPM but once hot, it idles faster.

Does this sound like a bad part?

What part?

Or is there a home remedy, sorta like the screw I used to turn to
adjust a carburater?

Thank you.

Allan
'89 240 196K daily driver
'84 240Ti project car from h*ll

 

First thing to do is clean out the idle speed regulator, it's a cylendrical
thing near the intake manifold, has two rubber hoses coming out of one end
and going to each side of the throttle body and a cable plugged into the
back end. It's a motorized valve that allows air to bypass the throttle
plate to regulate the idle speed.

 

If she's too much trouble I'll take that project off your hands, where
can I pick'er up?