1998 1999 2000 2001 Accord Coupe 3.0 V6 Low or Erratic Idle

[hughezee]

Retro Rich's coupe has developed the IAC valve issue now so I will follow up with some pic's soon 👍

[Cryistic]

I have a lot more confidence in your ablity to fix it over mine 

 

Can you rob parts off Purple haze to fix this or do you have a spare?

[hughezee]

Hopefully I can free off the existing valve

[hughezee]

Quick video of the before and after cleaning the idle air control valve, check out this DIY topic for tackling this cleaning procedure yourself

 

 

[Retro Rich]

Good Evening fellow members,

After mentioning to Stuart (some time ago) that occasionally, my idle speed is slightly erratic on the V6 after being parked up for 10 mins, he presented me with a new idle control valve for Christmas. I took the opportunity yesterday to fit this. My what fun. With temperatures near freezing, I sure chose the right day. I started by disconnecting the battery earth and removing the air box lid and filter.

I was careful to disconnect all the sensors in the vicinity that I could potentially damage. Just to keep me amused, a pipe clip that I had undone fell down into the bowels of the engine, prompting me to halt the job and conduct a search whilst wearing a head torch. After fruitless hunting, I decided to remove the battery and battery shelf to aid further search. This involved freeing the expansion bottle and un-clipping the cruise control cable.

Removing the battery was useful as it enabled me to see into the crevices better and I soon spied the rogue clip. I decided to remove all the clips I had released (where necessary) and put them aside to save being lost.

I found the task of removing and replacing the valve a nightmare, using locking pliers to loosen the valve screws. I found out much later from Stuart that I would have saved time removing the entire intake assembly. That said however, if I did another one of these, I'd procure a 90 degree Philips screw driver, or modify an existing straight one.

 

After finally replacing the valve, and losing more coolant than I would have liked, I injected some concentrate directly into the valve using a syringe and reconnected all the hoses.

As daylight was fast being lost at this point, I picked up the pace in putting everything back together and broke the earth cable hoop where it joins the chassis. Using a jump lead to bridge the gap, I started the engine. I spent considerable time burping the system, which in hindsight probably wasn't necessary. I then remade the earth connection. The result was fabulous, and smoothness, acceleration and torque all seemed to be improved. Also, there is no more erratic idle as previously described.

 

[hughezee]

Great follow up pal, although surprised you did the job the hard way and don't forget your ATF filter is due at the end of the month

[Cryistic]

I've spent time fiddling with these before and if your replacing the ICV with the throttle body in place then a small 1/4" ratchet with an adapter to take the right kind of screwdriver bit made the job a lot easier, 90° screwdrivers are a pain.

 

I can second Stus recommendation the remove the throttle body and replace the valve that way, this means any coolant leaks are easy to see and the location of the gasket is easy to see.

[Laird_Scooby]

Nice work Rich! It's amazing the amount of room you have with the battery and airbox out of the way - i'm sure last time i had the battery and airbox out of one of mine i disturbed a family of elephants!

[hughezee]

Finally managed to clean IAC valve and replace gaskets and as it turns out it wouldn't have been long before the one on the intake had failed as I suspected.

Scrapped off the old gasket and surfaces all cleaned and then wet sanded with 800/1000 grit paper.

Also replaced the throttle spacer gasket with the upgraded coated metal gaskets. (not pictured)

Now running better than ever,  so obviously, it needed doing.

[Andy Mc]

For the first time my Honda gave me cause to pause and pay attention to what was going on, even turn down the stereo!

Hot or cold on start up idle was really struggling, almost cutting out when in gear and rolling. Revs not bouncing up and down or high like in the video. After a few taps on the accelerator and a few mins drive it disappeared and would sit humming away. Just never had it before but then suddenly several times yesterday, so concerned if its going to increase until 'pop!' And a no start or something. 

Is this going to be the most likely place to start poking about? Or a shot of carb cleaner into the intake first and see if that helps clean up a sensor or two?

[hughezee]

5 hours ago, Andy Mc said:

Hot or cold on start up idle was really struggling, almost cutting out when in gear and rolling

My guess is a fuel delivery issue rather than a air issue and fuel relay would be top of my list, secondly ignition switch or coil going bad, even the dizzy cap can give idle or drivability issues.

Worth checking out this topic m8y: https://honda6.ipbhost.com/topic/6179-not-starting-no-start-1998-1999-2000-2001-cg-accord-coupe/

 

[Laird_Scooby]

I would wait until the fuel is down to 1/4 tank and then add :

https://www.toolstation.com/methylated-spirit/p99550

Give it a few days driving before adding some decent petrol but you should notice a result fairly quickly if it's what i suspect it is - condensation in the tank. This will be most obvious when stationary and particularly after a cold start. If you have been driving and join a queue of traffic or have to wait at lights or similar, it will idle ok to start with and gradually get worse as the condensation settles back in the bottom of the tank.

After an overnight stop, there will be neat fuel in the system so first start will be ok but a few seconds later when it starts pumping the water (condensation) mixed with fuel, you will get a poor idle. Driving will shake it up and move it around hence it will be ok for a bit after coming to a stop.

If those symptoms sound familiar then it's worth throwing a tenner at it to potentially cure it. For some reason metal tanks seem worse than plastic tanks for it, perhaps because they are colder.

[Andy Mc]

Happened st cold before i went to the petrol station and brimmed it. Then again after a 20 min drive and then again after another 20 min blast.

Because its been so reliable I've not spent an awful long if time under the bonnet. Will look for dizzy cap etc cheers! Think the last dizzy cap I messed with had the rotar arm and points inside that needed cleaning. I'm guessing these are a more electric set up? 🧐

[Laird_Scooby]

Shame you brimmed the tank, you'll have to wait until you're down to 1/4 now before trying the meths. Those symptoms add up, especially if you've not used it a great deal because of lockdowns etc.

Run it after dark with the bonnet up and you'll soon see if it's a dizzy cap/HT lead problem as there will be little blue sparks floating around in the problem area.