Avensis Petrol 2003 Vvti - Revs Drop When Stopping.

[craynerd]

Hi guys, I have a avensis 2003 Vvti petrol and the revs really drop just short of stalling when pulling up to the lights or such. The Revs drop right down and it feels like it's going stall but it doesn't, the revs pull back up after 5-10 seconds and it idles ok at 800 revs or so. If you are in traffic for a long time, it sometimes drops back down again for another few seconds. It certainly isn't getting better and already, reading the forum posts I have already:

Changed the spark plugs (with toyota supplied Iridium denso plugs)

Changed air filter (toyota supplied)

Cleaned the MAF sensor (was covered in black crap but didn't help!)

Any thoughts as to what else I can try? Any help appreciated.

Chris

[gazza1286]

https://youtu.be/i82s4ZfR2js

The idle control valve on the throttle body may be causing the issues. This is a by-pass to allow air flow when the butterfly is fully close. The air hose needs removing and the area sprayed with carb cleaner. Dismantling beyond this shouldn't be necessary.

The link above relates to a Camry but the principle is the same.

[craynerd]

Fab, will give that a go tomorrow

[craynerd]

Ok, I have a problem!

I'm going off the video link given and other videos, it shows a little hole next to the throttle body which bypasses to the idle control valve. The videos show squirting carb cleaner into the hole. However, I've dismantled down to the throttle body and the cylinder in which it sits is solid, there is no hole... Is my idle control valve positioned differently?? Will it be obvious if I fully remove the throttle body?

Help greatly appreciated. I have to take the family out now but will hope to continue this afternoon.

Chris

Edit: just found this picture, mine looks identical.

http://i.ytimg.com/vi/wNKX1p3FbBA/maxresdefault.jpg[\img]

EDIT 2: I've delayed the family trip and removed the throttle body fully. There is no obvious bypass valve like in the videos I've seen! The throttle body itself was gunked up badly so I've cleaned it all off. Anyone help and tell me where the idle control valve is to clean!

[gazza1286]

That still relates to this video (which no doubt you've watched)

Watch "Toyota Avensis Throttle Body Cleaning and Air Filter Replacement" on YouTube

https://youtu.be/wNKX1p3FbBAhat still relates to this video

The throttle body for that model differs from others fitted to Toyotas where the ICV is more obvious. Cleaning the housing itself may actually solve your problem.

[craynerd]

Hi Gaza, I really appreciate your help and anyone else that wants to chip in but I'm still not clear what you mean. Yes, I've watched the video and it appears identical to mine with no ICV obvious - I know cleaning the throttle body may improve my issue but although mucky I'm not sure it was that bad. While I've got everything dismantled I'd like to try and clean the the idle control valve - do you have any idea where it is from here?? I'm in the same position as he leaves it at the end of the YouTube video with everything dismantled.

[gazza1286]

I suspect the ICV mechanism is the plastic housing riveted to the casting. it appears to be tamper-proofed unlike other Toyota designs which can be unbolted/dismantled. Logically however there should be some type of by-pass to cater for air flow when the butterfly is shut. This should be able to be cleaned without dis-assembly.

You may want to consider swapping the entire unit for a salvage part - there's loads on eBay.

Good luck.

[craynerd]

Cleaned and reassembled and the car is running sweet as a nut. Revs we're running too high at first but they seemed to have settled now. Thanks for all the help.