Idle Problem when warm on autobox

[exec]

Sup y'all

My Dad has a 2.0 Auto and since he bought the car 2 years ago it has always had a problem which we at first suspected was a gearbox issue, but 2 years on and the gearbox is still kicking alive and well which indicated it might be something else causing it, so I recently bought an OBD adaptor and checked with the Touque app for any interesting stats and then noticed a problem with the idle revs.

Anyway cut the story short the problem is when in any of the drive gear eg D4, and after the car has become warm, when your say waiting in traffic and idle the car does a jumping action every 10 second or so and when you move off it kicks/jerks into action. So when inspecting the revs on the car i noticed it goes very low to around 4-500 revs before something kicks in to stop it from stalling and kicks it back to 7-800 revs, this is why it jumps around. So this suggests possibly idle issues, when my dad took it to the mechanics long time ago they cleaned the IAVC and said its normal, which it isn't. So am wondering if any of you knowledgeable folks might not any possible causes and fixes?

Something I wanted to try is check the Fast Idle Valve going from Ericthecarguys advice, but anyone know where this is located?

Cheers

 

[shab_the_man]

Dont think the 6th gen has a fast idel problem. From what you describe its the idle valve thats kicking in when the revs get too low.

How was the idle valve cleaned, did he take it right off? I know they are a pain to get to, they are located on the back of the inlet manifold with little space for spanners

 

[AndyB1976]

A friend of mine had a similar issue on his 6th gen Auto. I told him to look at the IACV but he wanted to go to the garage for them to look at it, and they apparently found a faulty injector.

I'm not sure of you can probe the injector for voltage switching (don't know the technical term) or listen to it via a stethoscope. Might be worth a shot if the IACV is clean.

 

[exec]

Note sure how the IACV was cleaned, my dad just gave the car to mechanics to look at who said he cleaned it, whether he actually did or not is another question. Wouldn't mind cleaning the IAVC myself, but it sounds like its hard to get at...

For the faulty injector would that have an error code to it? or any other symptoms? The car in general runs sweet, no performance issues when its on the go or anything.

The trouble is really finding a decent mechanic these days, most round here seem to be monkeys or liars.

 

[AndyB1976]

I wish I had more knowledge of the friends car...I'll ask if the management light was on.

I've had a look at getting to the IACV, I think the throttle body might have to come off because I tried offset spanners, long spanners, standard spanners and flex spanners . Throttle body has 4 nuts/bolts.

Have you cleaned your throttle body at all? I gave mine a blast of throttle body cleaner last year and quite a bit of gunk ran out which might give an indication of how the IACV is. You could undo the jubilee clip and ease the snorkel of the throttle body and have a look in at and beyond the butterfly valve.

http://www.lingshondaparts.com/honda_car_parts_selection_pfk.php?block_01=17S1T01&block_02=E__0101&block_03=2653

 

[exec]

Throttle body hasn't been cleaned afaik, might be worth it i guess, whats the best material to use to clean it?

Thanks for having a look, seems like a bit of a pain to get to!

Would a Honda dealer charge to diagnose the problem?

 

[AndyB1976]

I bought Wynns Air Intake cleaner from Halfords. It wasn't specifically recommended, I just decided to give it a try and it seemed to clean up quite well.

http://www.halfords.com/webapp/wcs/stores/servlet/product_storeId_10001_catalogId_10151_productId_202903_langId_-1_categoryId_255221#tab1


Honda diagnosis.....I've heard some prices like £90 per hour on various forums, so I guess that could be a good estimate.

 

[exec]

£90 ****** hell lol think that option is out they way, some diy cleaning might be in order, would valve clearance do any help, not sure what other intervals they are meant to be done, my dads has 60k on the clock, afaik VC needs to be done at 81k?

 

[AndyB1976]

Give your Honda dealer a call just to confirm that price, as I say its just figures I've heard banded about forums, doesn't necessarily mean its accurate.

I don't think your valve clearances would cause erratic idle. Its worth checking them anyway but it is maybe a two man job unless you were experienced with the feeler gauge. I done mine a few weeks ago and its was a bit awkward considering the accuracy required.