Idle rpm adjustment

[Hlkh]

Hi have anyone try to adjust the idle rpm before?

now all car have ecu how to adjust?

 

car :

Lancer 04 cs3 manual transmission

[Forhod]

If my memory didn't fail me, there is an idling screw located somewhere around the throttle body area to adjust the idling rpm.

 

Do you really need to adjust it though?

[Hamburger]

now all govern by ECU oridi.cant adjust liao

[Forhod]

Is it? My bad..

[Hlkh]

yeah ... bro you are right, i try to adjust den later the ecu control back to original rpm.

if wanna set idle rpm wat are the way ?

[Lucien]

Why u want to adjust?

 

ECU does not control the idle RPM.

Its the IACV that controls ur idle RPM.

Want to tune it, change the IACV.

Edited September 13, 2007 by Lucien

[Hlkh]

Sorry .... wat is IACV?

[Garlic]

Source: http://autorepair.about.com/cs/generalinfo/l/bldef_333.htm

 

Idle Air Control Valve

 

"An electrically-operated valve which allows air to bypass the throttle plate in a fuel injected engine to regulate engine idle speed."

 

[Hlkh]

hi ... thanks for the infor.

but i have found a adjustable screw beside the throttle position sensor any ideal what is that for?

[Orixy]

The idling screw for the cs3 lancer is on top of the throttle body, covered with a small black rubber piece. Remove the rubber and you can see a + screw inside. Turn clockwise to decrease idling speed and anti-clockwise to increase.

 

Hope that helps! :)

 

Anyway, why would u need to adjust idling speed?

[Hlkh]

Actually my ride rpm idle around 800rpm and some time slight vibrate abit....

just wanna increase till 850rpm like tat so wont have the vibrate feel

i have try adjusting it, but after awhile the idle rpm go back to normal 800rpm within 1 day.

[Orixy]

If rpm at idle vibrate occasionally, probably time to clean your throttle body and especially the idle air control valve (IAC).

[Vidz]

i believe ECU have the final say...

[Orixy]

"i believe ECU have the final say.."

 

>>> hmmm... somewhat I do agree with you. The idling screw is the mechanical component that controls idling speed. So if I set it to idle at 1000rpm, the ecu will tell the IAC to allow more air in so that rpm reads at 1000rpm.

 

Why I said somewhat is becos the idling screw does play a part in idling as oppose to saying that the ecu have final say.

[Hlkh]

the idle air control valve can diy clean anot?

[Hlkh]

ya ... this is what i feel too everytime adjust after sometime the idle when back to original

[Vidz]

i think ECU still controls the air-fuel ratio, etc...

so it will compensate watever adjustments to a certain extend

 

unless a carb car then diff story...

Edited September 20, 2007 by Vidz

[Orixy]

sure can DIY clean. Use some carb spray that normally used to clean TB to clean the IAC. Done it a couple of times before and everytime it never fails to make the idling better