My idle won't go low enough to pass emissions test

I failed the emissions test, solely because the idle speed wouldn’t go low enough. It passed easily at high speed. It’s been passing emissions tests for 30 years.

I got it home, turned the idle screw all the way out; it didn’t slow down. I turned it many turns in; it eventually sped up (so I have the right screw; I’ve done this before.)

What’s up? I haven’t driven it in a year, but that’s usually the case.

Nobody can say.

Nobody knows what year this Toyota pickup is.

Tester

Sorry. 1987 XtraCab Deluxe long-bed 4-cylinder carbureted 5-speed manual transmission, red, AC (broken years ago, never fixed)

You might be looking at a carb rebuild.

The ethanol in today’s gasoline can damage the rubber components/pot metal carb body.

In Minnesota, we can purchase non-oxy gas just for this reason.

http://msra.com/wp-content/uploads/2016/12/Jan-2017-Non-Oxy.pdf

Tester

The choke was stuck. 15 years ago it froze (17 below) and the arm attached to the bimetallic coil popped out of its seat. It was riveted on. I had to drill out the rivets, put the arm back into the coil’s loop, thread it for gauge 6 screws, screw it on. It’s held up until now.