DIY - 1.8L 1ZZ-FE TB Connector Chip Swap

[tk-421]

Originally Posted by MGargano

So I should turn it all the way in, then back out 1.5 turns? If not, what's the 'correct' procedure for adjusting the idle screw?

1. Turn engine off
2. Adjust the screw to your liking
3. Turn engine on and test for oscillation and high idle
4. If you need to modify the value, go to step 1
5. If you're satisfied with the setting, throw some epoxy in there and let dry (optional, but recommended)

FYI, I've read that it's better not to try adjusting the screw with the engine on, or else the ECU might need to be rebooted one last time to reset the values.

I had no idea which direction to turn to or anything like that... All I did was turn clockwise until I found the best setting after the second try. I guess I got lucky, because the damn screw got stripped at a very decent setting, so I didn't need to do any tweaking afterwards.

I also let the gasket maker do its thing for at least 4 hours IIRC, with the battery disconnected the whole time. I also did the coolant bypass, but didn't need to burp it afterwards.

No big oscillations, no CELs, and a pretty decent 2.5K idle... could've been a bit better, but I'm not complaining.