2000rpm Idle

[sky_high_psi]

hey guys i just replaced my injectors in my rb20, they were the same size as the previous ones,

whilst doing this i cleaned the AAC

once all back together i started it up and it idles at 2000rpm, i followed the d.i.y http://www.skylinesaustralia.com/forums/Di...nd-t110431.html here and attempted to change the idle, going by the tutorial when i have removed the electrical connector on the AAC unit my car idles at 900rpm, so i assumed that the computer needs to be adjusted as indicated by the tutorial, when i turn the little screw on the comp it does nothing

any suggestions as to whats wrong?

one possibility that i thought is that although the injectors are the same capacity as previous they are in much better condition and may flow better, could this be the cause of the high idle?

[drf76]

hey guys i just replaced my injectors in my rb20, they were the same size as the previous ones,

whilst doing this i cleaned the AAC

once all back together i started it up and it idles at 2000rpm, i followed the d.i.y http://www.skylinesaustralia.com/forums/Di...nd-t110431.html here and attempted to change the idle, going by the tutorial when i have removed the electrical connector on the AAC unit my car idles at 900rpm, so i assumed that the computer needs to be adjusted as indicated by the tutorial, when i turn the little screw on the comp it does nothing

any suggestions as to whats wrong?

one possibility that i thought is that although the injectors are the same capacity as previous they are in much better condition and may flow better, could this be the cause of the high idle?

it may be possible but have u tried adjusting the screw on the aac valve itself...

[Moodles2]

Reset the ECU if you haven't done it already

[sky_high_psi]

if i reset the ecu wont i lose my tune?

[blind_elk]

Resetting will put it to a default / factory setting (this is of courcse assuming you are running the factory ECU).

The adjustment on the ECU is a fine adjustment. The adjustment you need is on the base of the AAC valve.

Did you replace the gasket on the AAC valve - high idle is indicative of an air leak.

[ezy_09s]

sounds like an air leak somewhere...check all hoses etc.

Was the idle normal prior to the injector change?

[sky_high_psi]

i replaced all gaskets with gasket glue, the idle was fine befor i did the injector change and when i unplug the electrical connector on the aac valve it idles back on 900rpm which is what im after but once i plug it back in it goes back up to 2000

perhaps ill adjust the aac valve when the electrical connector is plugged in

[sky_high_psi]

iv played with both the valve on the aac unit and the one on the ecu with no effect, iv checked for leaks and i cant find a thing, is it possible that it is due to the tune(when i had the car tuned the injectors had a leak and therfor more fuel was needed for start up and im assuming idle) could this cause the high idle iv got now considering these injectors are not leaking?

[Kwyjibo]

Check your idle on startup, if it is the same as when warm then it is likely to be your IAC valve and it often causes problems. You'll need to pull of your main intake pipe and its best to remove the throttle body as well as it sits underneath this. It has a hose running to the bottom of it and one to the top.

The problem is the valve is pulled shut by a spring by default. This spring often deforms or snaps so the valve remains open when engine is warm and is constantly delivering too much air and raising your idles. You can open up the IAC and reseat the spring.

Edited June 1, 2009 by Kwyjibo

[sky_high_psi]

yeah hot or cold it idles at 2000, i was having a look today and your not talking about what i have circled in red are you? cause thats all i can see underneath the throttle body?

[pipster11]

thats the one

also try the tps plugs, just wiggle them

i had my idle valve holding itself open causing 2000rpm idle

what did you remove to get the injectors out?

[sky_high_psi]

to remove the injectors i had to take out the cross over pipe, throttle body and the aac unit.

i didnt touch the component i have circled in the pic but ill pull it apart this w/e and have a look

[(B1) MR_fanny]

id like to know how you go with it. my revs have been playing up too. cleaned the AAC but it came back 2 months later. Cleaned AFM and that fixed it for about 2 weeks. Car would idle normally on first startup and then play up after abit of driving. Could a possible leak from the vacuum hose that goes into the EBC be the cause?

[sky_high_psi]

pulled it apart yesterday, the little spring was in perfect working order, turned out to be the little sensor thing that is attached to the throttle body, when you pull it apart it is conected to the throttle so i shifted it slightly which caused idle to drop to where i want it

[(B1) MR_fanny]

which sensor was this? any chance you can post up a pic of it? ill have a poke around tomorrow and see how i go

[sky_high_psi]

yeah ill post up a pic on thursday(gotta wait for sis to get back with camera)

[sky_high_psi]

this is the little sensor i played with that seemed to solve the problem

(not my engine bay-couldnt get my hands on a camera)

[(B1) MR_fanny]

cheers mate. ill have a fiddle and clean with mine

[predator]

That's the Throttle Position sensor (TPS). If you have a CONSULT cable or an aftermarket ECU you should be able to check if the voltage is in range.

[jnr_chin]

straying a little the valve underneath the throttle body (IAC) does it have anything to do with the A/C throttling up when it is turned on?

when i turn on my air condition it throttles down the car and sometimes coming to a stop it shuts off. i cleaned the one to the back of the plenum and i have seen no change. what could it be?