2006 Accord CL7 idle problem
 

Hi there. I m driving a Honda Accord CL7A, much like the EuroR but with auto transmission. Lately my idle seems to be having some problems. Sometimes its is perfectly ok but occasionally the idle drops to 500rpm and when i step on the accelarator, it will dip/hesitate n then it will move off! Tried cleaning the throttle body n the IACV but problem still persists. I also realised that if i turn off the air conditioning, sometimes the hesitation before moving disappears. But sometimes its still there! Is it because of faulty IACV? please help...

Your symptoms certainly suggest idle speed control problem.

On earlier models, and probably yours as well, it is important to clean the throttle plate (both sides) w/ throttle body cleaner to allow some air past the throttle plate.

You don't say, but it is assumed you don't have a Check Engine Light. If yes, you need to get the Pnnnn code and repost.

Clean the IACV valve movement and air passage w/ throttle body cleaner.

I checked the Honda Shop Manual I have and it has a precaution not to clean the bearing area of the throttle plate shaft and to use only Honda throttle plate and induction system cleaner. Manual recommends removal of throttle body for cleaning. It also precautions against spraying throttle body cleaner "directly onto the throttle body". Presumably they mean the exterior, since you have to spray the interior to clean. It may be best to clean w/ a paper towel soaked w/ throttle body cleaner.

If you don't have a Honda Shop Manual, I would recommend one. One mistake prevented will pay for the manual, ~$100 as I recollect.

good luck

Thanks TexasHonda, i will try out your recommendation.

Correct me if i m wrong, but the IACV is the one located at the bottom of the throttle body, right? The one with 2 hoses for the coolant to run through. Am i right?

So what does the other one, located on the other side of the throttle cable swindle, do? Its located on the outer part of the throttle plate, black in colour has 2 screws that you can loosen to adjust the idle timing. Its doesnt have any hoses or anything, only a male/female three pin connector. I checked and its called the IACV too.. Very confused now....

Yes, IACV is on bottom of throttle body.

I think you're referring to throttle position sensor, which measures throttle plate angle for ECU control of fuel/air.

good luck

Thank you so much for your explanation. Now i understand.. So do i do anytng to the throttle position sensor? (Like adjust it to make the idling go higher)... How do i adjust the IACV because the space is so small.. Do i reset the ECU?

hi
 

to reset IACV get your stuff to some service center they will do that better :)

You don't adjust Throttle Position Sensor.

If you want to do this, you need the shop manual to guide your work. It will require removal of throttle body (based on my reading).

My earlier instructions give a high level view of what needs to be done. If you think you need more help, the manual is best support.

good luck

Roger that. Thanks TexasHonda.

Hey there, I have already clean the TB with TB cleaner (gosh! it was so dirty!). I will be fixing the TB back in the car and hope everything goes as planned.

By the way, I remembered reading a post teaching u how to reset the ECU and force it to re learn the idle.. Can someone please run by me again the steps. And they mentioned something bout taking out the 7.5A fuse to reset the ECU n placing it in again. Which 7.5A fuse is it? Is it the one in the fuse box in the engine bay or the one in the interior beside the driver's seat? Do i take it out when the engine is running or when it is not?

Not sure if removing the 7.5A fuse will reset ECU in 2007 model, but if it does the fuse is removed w/ engine Off.

I'll check my manual and see if any guidance on resetting ECU is provided.

After some further reading, I'm fairly certain that removing a fuse will not reset the ECM. I do believe you need an idle relearn procedure based on reading the manual. Here's the procedure:

1) Make sure all electrical itmes are OFF.
2) Reset the ECM/PCM w/ HDS (you will need a generic scanner to reset the ECM)
3) Turn the ignition switch ON, and wait 2 secs.
4) Start engine and hold at 3K rpm w/o load until radiator fans come on or until coolant temp reaches 194F.
5) Let engine idle for 5 mins w/ throttle fully closed.

good luck

1) Make sure all electrical itmes are OFF.
2) Reset the ECM/PCM w/ HDS (you will need a generic scanner to reset the ECM)
3) Turn the ignition switch ON, and wait 2 secs.
4) Start engine and hold at 3K rpm w/o load until radiator fans come on or until coolant temp reaches 194F.
5) Let engine idle for 5 mins w/ throttle fully closed.

Hi TexasHonda.. Thank you so much for the input. I will try out this procedure and get back on the outcome.

Quick question, if I do not have a generic scanner or HDS to reset the ECM, can i just unhook the negative cable on my battery for a minute or so?

The Honda manual did not say anything about disconnecting battery to reset ECM. You can try googling for a procedure would be my only suggestion.

good luck

I used to have a 2003-2006 Helm book & I think I remember it saying that disconnecting the battery did NOT clear OBD-2 error codes. But maybe it does clear things like idle adaptation??

Hi guys, I finally found the time to try out the ILP on the car a few days ago. So far it went GREAT!! The idling was perfect and the hesitations before moving off were nowhere in sight.... I was just about to do a write up on the forum to tell you guys about the success I had......

But then, yesterday, THE IDLING STARTED TO DETERIORATE WHILE I WAS AT A TRAFFIC LIGHT and when i step on the accelerator, the RPM dipped and went to 300 RPM before going up and moving off!!

Let me give you the scenario I was in: The day was scorching hot and I had been driving in the city (stopping at a lot of traffic lights) for about 2 hours or so... The car was running at 176F-194F and the air conditioning was ON.

So this was what I did: I turned OFF the aircon and wound down the windows..

After a few minutes more of driving and at the next traffic stop, THE PROBLEM WAS GONE!! The idling was back at 600-650RPM and I had no problems moving off!

Could it be that there's something wrong with my aircon motor or something?? If so, why doesn't the problem surface the minute I switch on the air conditioning? I realized it will only start acting up after some time on the road and after a few traffic stops, when its idling..

Oh and another thing, after doing the Idle Learning Procedure, I realized that my petrol consumption was affected.. Used to get 29 miles per gallon of petrol, but after the ILP, it went down to 21 miles per gallon!! What does it mean guys? Did the ILP had anything to do with it?

Does IACV compensate correctly most of the time, holding idle speed at constant value as AC cycles on/off? If idle speed sags when load is added, the IACV is not compensating for some reason.

You may have a faulty idle air control valve (valve movement sticking or weak solenoid). It may be working sometimes, but under hot conditions may be failing causing lack of idle air bypass to increase idle under load (AC on).

Note, ECM cannot detect a sticking valve. Also, the ECM will detect a shorted or open idle air control valve solenoid and set a code, but probably not an internal winding short that simply reduces solenoid strength to throw the valve.

It's not surprising that idle was stable when everything is off. This reduces variable load so base idle speed is maintained.

Change in mileage is not likely related to idle problem, IMO. It may take more time for ECM to optimize fuel metering.

good luck

Thanks TexasHonda... So its settled then that my IACV is the culprit. How do I get my hands on a new one? Can u direct me to a reliable website that sells one?

For your info, I am living in Asia and my country doesn't sell the IACV by itself. The suppliers here claims it comes as a complete set with the throttle body and the throttle position sensor... ( I think they just wanna make a quick buck coz the whole assembly cost a bomb! ).... Is there any way I can just the IACV on the net?

Thanks so much for your help....

check ebay auction 110616065709. Ships worldwide.

Depending on effort involved, I would remove/examine the IACV carefully. Does the solenoid throw when 12V is applied? If not perhaps there's still some stubborn deposits blocking movement. I would also check the voltage pulses are getting to the IACV to actuate. Poor connection might not be detected but cause weak valve movement.

I am not a professional, just an amatuer w/ some knowledge who enjoys diagnostics and repair.

In other words, make sure this is your problem before ordering parts.

good luck

Hi TexasHonda, I hav done all the checks that you recommended and everything seems to work fine. I even check the throttle position sensor and its showing 0%, which is what it should be at idle. The funny thing is, the idle will be just fine when its stationary and idling, even with AC on and all. It will just come once in awhile when i am driving, sometimes its doesn't come at all.. But when it does, I am always in the middle of traffic and I cant be stopping right there to do my checks... And when i get home to my parking lot, the idling would have gone back to normal..

I think the safest bet for me now is to get a new IACV. I went to check at hondapartsnow,com and I found it under parts number 16400-RAA-A63, which is the complete assembly of the throttle body.

I just need the IACV, and they have it!!!... Its under part number 16022-RAA-A01 (Valve Set, Rotary Air Control) and 16456-PND-A01 (Gasket, Rotary Air Control Valve).....Only bummer is they don't ship it to the country I am in.. They only ship to the 50 US states.

Could you perhaps get them for me and ship them to me? Since you are in Texas.. (I presume).. I would bear all the cost and the shipping. Or i could buy it online and send the item to your US address, and you could UPS it to me?

Suggest looking for someone that will ship abroad. Here's one I found (yourhondaparts^com).

regards

OK... Thanks so much TexasHonda for your helpful advice...God Bless you.