Clubjazz - Honda Jazz & HR-V Forums

Honda Jazz Forums => Honda Jazz Mk1 2002-2008 => Topic started by: piercedpanda on September 22, 2017, 12:38:39 PM

Title: Idle at 1500 rpm
Post by: piercedpanda on September 22, 2017, 12:38:39 PM
My Honda Jazz has an idle speed of 1500 rpm.
When I drive and put it in neutral, it revs between 1000 en 2000 rpm.
Recently the battery was replaced.
Is there an idle learn procedure to follow for a Jazz ?
Or is something else wrong ?
Title: Re: Idle at 1500 rpm
Post by: Jocko on September 22, 2017, 02:25:56 PM
Is there an idle learn procedure to follow for a Jazz ?
Not that I am aware of. I changed the battery with no relearning of any parameters.
There was another post here, along similar lines. Search for that and see if there was any conclusions.
And welcome to our forum. Lots of good advice to be found here.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 22, 2017, 02:37:49 PM
Is there an idle learn procedure to follow for a Jazz ?
Not that I am aware of. I changed the battery with no relearning of any parameters.
There was another post here, along similar lines. Search for that and see if there was any conclusions.
And welcome to our forum. Lots of good advice to be found here.

I think you mean this one ?
https://clubjazz.org/forum/index.php?topic=2542.msg10946#msg10946

I've read it, but no conclusions were posted, sadly.
Title: Re: Idle at 1500 rpm
Post by: Jocko on September 22, 2017, 02:51:28 PM
I thought it was a newer on than that. I have never read that far back. I'll try and find it.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 22, 2017, 07:34:53 PM
I thought it was a newer on than that. I have never read that far back. I'll try and find it.

Found it yet? ;)

I took a look under hood and have found where the iacv is located.
Would it be a good thing to start with cleaning that?
And if I take it off, would my gasoline start to leak out?
Title: Re: Idle at 1500 rpm
Post by: Jocko on September 22, 2017, 07:50:15 PM
Have not been able to find it.
Title: Re: Idle at 1500 rpm
Post by: Jocko on September 22, 2017, 08:04:51 PM
Found this interesting article.
http://www.wikihow.com/Check-an-Idle-Air-Control-Valve (http://www.wikihow.com/Check-an-Idle-Air-Control-Valve)
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 22, 2017, 08:17:45 PM
Found this interesting article.
http://www.wikihow.com/Check-an-Idle-Air-Control-Valve (http://www.wikihow.com/Check-an-Idle-Air-Control-Valve)

So that would be a first check, disconnecting it.
I’ll see if I can try this tomorrow then.
Thanks!
Title: Re: Idle at 1500 rpm
Post by: sparky Paul on September 23, 2017, 08:37:31 AM
Idle Control Valves can soot up and stick. Use carb cleaner, or at a pinch a bit of clean petrol - nothing with any trace of oil in it. Also make sure that the gasket is good, and replace if necessary.

Also check around the inlet manifold for leaks, in particular the vacuum pipework to the brake servo, as these can split and allow air in,  affecting idle speed.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 23, 2017, 12:13:59 PM
Found this interesting article.
http://www.wikihow.com/Check-an-Idle-Air-Control-Valve (http://www.wikihow.com/Check-an-Idle-Air-Control-Valve)

So that would be a first check, disconnecting it.
I’ll see if I can try this tomorrow then.
Thanks!

I’ve tried this method, but that didn’t have much effect.
When I disconnected the plug, it ran even a little worse, revving up and down around the 1500rpm.
There’s a lot of wires and hoses, so I don’t really know where to look next  :'(
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 23, 2017, 03:04:10 PM
And now the egine management light is on...
Weird...

The car is gonna go back to where I bought it on Thursday to get a checkup.
Title: Re: Idle at 1500 rpm
Post by: sparky Paul on September 23, 2017, 08:33:27 PM
Unplugging the ICV will probably put the EML light on on the Honda. It certainly won't idle right.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 23, 2017, 09:57:25 PM
Unplugging the ICV will probably put the EML light on on the Honda. It certainly won't idle right.

That’s what happened indeed..
What to do next ?
Title: Re: Idle at 1500 rpm
Post by: sparky Paul on September 24, 2017, 12:15:48 PM
The ECU will have flagged up that the valve is disconnected, EML will probably reset after a few days.

To be honest, there's no easy diagnostic for the ICV. Ideally, you need to make sure the valve is clean and that everything is moving freely, and check for fault codes. Alternatively, rule it out by replacing with a known good one.

The most likely cause is that excess air is getting in somewhere to raise the idle speed. Either the throttle or ICV is not closing properly, or there is an inlet leak.

Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 24, 2017, 01:24:52 PM
The ECU will have flagged up that the valve is disconnected, EML will probably reset after a few days.

To be honest, there's no easy diagnostic for the ICV. Ideally, you need to make sure the valve is clean and that everything is moving freely, and check for fault codes. Alternatively, rule it out by replacing with a known good one.

The most likely cause is that excess air is getting in somewhere to raise the idle speed. Either the throttle or ICV is not closing properly, or there is an inlet leak.

The garage where I bought it is gonna look into it on Thursday.
That guy is responsible for selling me a good car, like he said himself :)
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 25, 2017, 06:12:33 PM
The ECU will have flagged up that the valve is disconnected, EML will probably reset after a few days.

The light for motor management did indeed go out today.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 29, 2017, 02:42:47 PM
Got the car back from the garage today.
The inlet manifold was leaking some air, that was the problem.
Title: Re: Idle at 1500 rpm
Post by: Jocko on September 29, 2017, 02:53:09 PM
sparky Paul said that right back at the beginning. At least that's it solved.
Title: Re: Idle at 1500 rpm
Post by: piercedpanda on September 29, 2017, 02:55:04 PM
Yeah I know.
As a not very experienced car mechanic, I got a little scared with all the wiring and hoses :)

Glad it's solved though!

Thanks for all your help!
Title: Re: Idle at 1500 rpm
Post by: sparky Paul on September 29, 2017, 07:10:21 PM
It doesn't matter that you don't get your hands dirty yourself, I think it's always useful to have some idea what's what when dealing with garages, even if only to explain your problem better.

Additionally, if it looks like you might have some small idea what a mechanic is talking about, it tends to cut down on the flannel.  ;)