TooLateVTEC

iTrader: (2)

I need to bring my idle down about 100 RPM's, is it ok to try and use the screw in the T/B for this or do I need to have a tuner go in and do it through the computer?

It idles at around 900 and I just want to lower it like 50, maybe 100 RPM's to tame it down some.

Thanks

witry

iTrader: (8)

i think idle would be controlled thru the IAC motor only way to change it would be thru like hp tuners or something similar the screw is like a throttle stop with minimal adjustment

3800RS

iTrader: (15)

dont know. try it and see.

fxgs

iTrader: (2)

Yes, you can do it by turning the screw............then I suggest putting a couple drops of thread lock on it to keep it from vibrating out from what you set it at

jmm98LS1

iTrader: (28)

Idle speed is controlled only by the pcm, you cannot change it with the screw on the throttle body. All you do by changing it's position is let more/less air in at idle.....the pcm will compensate and close the iac motor to maintain it's programmed idle speed.

Wesmanw02

iTrader: (4)

Exactly, someone who actually knows

If you want to adjust your idle, you will need to have tuning software such as HP Tuners or LS1Edit.

mike13

iTrader: (27)

Do a search, I think there's a method where you set the idle and disconnect the tpis, turn they key, turn the key off and reconnect the tpis.

DaveX

Turning the screw without tuning will cause problems. All of your airflow tables will then be off. Like stated above, it's an airflow adjustment, not an idle adjust screw. Don't do it.

eseibel67

iTrader: (10)

Doing this will allow more/less air in at idle but will not adjust your idle speed. PCM will raise/lower IAC counts to acheive desired idle no matter where you put the screw.

mike13

iTrader: (27)

I better go out and tell my engine that because it doesn't know. Raised my idle by adjusting the screw, got a code for unexpected high idle, cleared it went out did the procedure with the tps and haven't had a code or pending code. Idle stayed where I placed it.

eseibel67

iTrader: (10)

This is possible. Your IAC motor is at the bottom limit and cannot take away any more air when it needs to. Ideally you want some range to work with.

69LT1Bird

iTrader: (1)

It is probably better to tell people the right way to do it.

mike13

iTrader: (27)

If that was the case it would still throw a code, by unplugging it and having the pcm recognize it's not receiving a signal it throws a code. Plugging it back in causes the pcm to calibrate for the "new" sensor.