Uneven Idle.

[Uncle_P]

Afternoon all. My Rav's a big sick..

The idle has been ocaisionally dropping too low and then it'll recover and be fine. It's not really bothered me before, but this morning the revs would rise to about 1400 and the drop to 600 over and over. It seems pretty much fine when running, only the idle seems affected.

So, is it my throttle body that needs a clean out? Is it worth trying a can of carb cleaner? I read an excellent pictorial guide on the forum about how to clean out the throttle body and icv, but I'm not sure if that's the problem here. Is there anything else that might cause this effect? Sometimes it seems to be fine and smooth and sometimes it struggles. I've run a load of redex through with the petrol, but it hasn't made any difference.

Any ideas chaps?

Bill

[Big Kev]

Howzabout the MAF sensor on top of air filter housing, Bill? Try cleaning spray on that........?

[LeeADAB]

Hi Bill.

If the throttle body and icv have not been cleaned before then its definitely worth doing.

Get the two gaskets first and remove as per the instructions to be sure its clean. My icv was quite carboned up and the throttle body was dirty too. Afterwards both looked like new Thanks to a toothbrush, rags and some Normfest throttle spray. Throttle response has been great since. that may solve the idle issues. If not - at least you know they are now clean.

[Uncle_P]

I don't think my mechanical skills are up to stripping down the throttle body, so it'll be my local garage that does that. Do you chaps think that I'm on the right track with the fault?

I'll try a can of carb cleaner first, but I can see a full strip and clean on the horizon. Good job I'm on overtime all week, it'll probably cost a few £££££s.

[Uncle_P]

Can anybody recommend a decent carb spray? Does the MAF just get a spray and clean with a cotton bud?

[Big Kev]

Seem to recall you just spray the wee bulbous metal element and let it dry fully. Apparently the fragility of the element does not lend itself to poking aboot with probes, Bill min.

[LeeADAB]

I used the Normfest VC980 which worked a treat In cleaning the throttle body and ICV.

See.... http://www.toyotaownersclub.com/forums/topic/136234-throttle-body-cleaning-fluids/

I wouldn't use carb cleaner on the maf tho. You want an electrical contact cleaner for that. There are two fine wires inside and one amber bulb sensor on the outside. Spray both sections generously and wait for fluid to dry. Shouldn't need cotton buds but just go easy if you do. I use PowRwashPR to clean mine.

[LeeADAB]

Throttle and ICV clean by Toyota dealer was quoted roughly £80 so you'll still have some overtime money for beers. I did mine myself as I wanted to know that they were spotless before refitting. Cost me about £16 for gaskets and the carb cleaner! Don't need to clamp off the two coolant hoses either as very little came out.

[Uncle_P]

The idle is still occasionally dropping too low even after removing the MAF and giving it a good spray with some electrical cleaner. I'm beginning to think that it might need the ICV cleaning or replacing. Maybe after Christmas I might get around to it. Are there any other common causes of a low idle? Mostly it's fine at around 800 rpm, but sometimes seems to miss a few beats and drop too low. Sometimes it recover by itself, sometimes it needs a blip of throttle. It's a small fault, I just don't wanting it turning into a big one!

Ever since I've owned it, when coming to a halt and putting the clutch down, the revs fall to about 500 and immediately bounce back up to a steady idle. Is this normal amongst other 2.0 petrol owners?

[gjnorthall]

It's usually the idle control valve that sticks - if you tap the solenoid - it usually frees it, but to prevent recurrence - you need to clean it internally. Whilst you can do a limited amount of cleaning of the throttle body in-situ, the ICV needs to be unbolted from the throttle body to clean it.