car reving up n down

[123R-Prozak]

ok, car was reving up n down today at the lights, rev needle must of moved 5 times up n down before settling, hasnt done it since, nor before, im thinking of doing a throttle body service on the car, aswell as geting electrical contact/terminal cleaner for the MAF ??

please somelet let me know if it may be something different or if i shouldnt do this...

doing a T/B service cause a DTC to set?? should i remove it and clean it with a tooth brush or do it in car then start the car with WOT.....

help appreciated, btw Cold Air Intake installed 9,200km ago...

have i hit the nail on the head with this idle prob?? or is it something else....

will a oil catch can fix this prob from re-accuring lol??

Edited July 18, 2009 by 123R-Prozak

[DJKOR]

Since it seems like a random occurrence, I wouldn't worry too much. It could have all kinds of factors that caused it to do that. If it happens again in the next week, I'd be alert, if it happens a third time, then I'd get concerned.

In the mean time though, it wont hurt to give the throttle body and MAF a clean. These could have well been the contributing factors, so you may not ever see the issue again. Is your CAI an oiled filter? If so, these can lead to a dirty MAF over time, and that may be more of the actual cause.

Cleaning the throttle body isn't really something that you can overdo. I usually clean mine every 15,000km when I change the air filter.

I prefer to use a clean cotton cloth/rag when cleaning the throttle body. Just hold the butterfly valve open and give it a good spray, then quickly get the cloth and wipe as much of all the surfaces as you can. Then get repeat. I then usually spray a clean section of cloth and give one last wipe over everything I can touch in there.

Cleaning it won't cause a DTC unless you start the car without connecting the piping to the MAF. No need to go WOT on start. Just try to start it normally, and blip the throttle while you are at it. Let it idle for 30 seconds, give it a rev or two, then stop the engine.

As for the catch can, have a look at the residue around the PCV piping to the intake. If there is a fair bit of residue, this could be causing your TB to get dirty, otherwise your air filter may be the main cause for the dirty throttle body. Depends on how dirty the throttle body is really.

[Guni]

Check the Idling control valve or your sparks first.

[AE102]

common problem - often the IMG is leaking. spray some card cleaner(cat safe!) around where the manifold bolts to the head and listen out for the slightest rise in revs to confirm leak. worth cleaning the maf - plugs dont cause rev hunting! if you dont find a leak remove and clean the iacv but that shouldnt be clogged - if your getting a lot of oil vapour from the pcv you've got bigger problems on the way.

[Suprathai]

Check the ICV, I think on newcelica.org they have a tutorial on how to clean it out properly.