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RPM idle has doubled to 1500 after battery reconnection!

sjec

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'05 accord 2.4i exec
Hi guys..

So after my welcome post. I decided to recharge the battery with charger. It read 12.77V or so on the multimeter. I reconnected just now. And now idle speed is 1500!!! Rather than than the 700-800 it was beforehand. What do I do? I turned it off and back on...and still the same high idle. Suggestions please....

Cheers
Steve
 
I would try reseting the ecu again by disconnecting the battery. It's possible its just got confused.
 
Hi
When disconnecting the battery you are forcing the ECU to reset itself. It needs time to recalobrate all its sensors. I would suggest taking it for a short drive and then levaing it to idle for 20 mins or so.
I remember on my old Accord when disconnecting the battery it would begin cutting out and then leaving it to idle for 30 mins it all came back into line.

Don't worry just yet, just follow what Ive said and all should be fine
 
Did you let the car warm up fully and settle down. Best advice would be to take it for a drive and allow it to get to temp and then see what it's like.
 
How does that happen CJ. I had my battery disconnected today and all seems fine. Is there an element of luck?

I did nearly deposit a brick when the Sat Nav screen came up with its red texted warning :lol:
 
I was gonna say.... I had the battery off for 45 minutes or more doing my iPod adapter and everything seems fine. Will go for a spin tomorrow at some point to check, but I am surprised that this could happen with no mechanical intervention.
 
CJ on one of my 6 th gen Accords the Battery was disconnected and when reconnected it would not hold idle at all. Just cut out straight away. I left it running for 30 mins and between that time gradually it learnt itself and fixed its own idle speed. Can this n ot be achived with this car?
 
Thanks for reply everyone. Pepster, I disconnected battery... -ve first. Removed battery from car. Connected to ctek battery charger overnight. Reconnected battery -ve last. From all my reading on here and elsewhere I thought your meant to leave it over an hour before reconnection anyway. Oh out of interest, any detrimental effect of a high idle?
 
I thought you should always disconnect a battery. I was told that the charger could damage sensitive equipment. On some more expensive cars (prestige German) they actually have charges on the positive to blow the terminal off in case of an accident.
 
Surely depends on the charger I would have thought? Also what if the charger develops a fault and sends a spike down into the battery. Just a thought.
 
What about jump starting? I am surprised there isn't some for of built in protection?
 
What about jump starting? I am surprised there isn't some for of built in protection?

My dad jump started his xtrial which he'd left at one of his homes in Spain. It started fine but was in constant limp mode. It turned out that by jumping it off it had spiked the throttle position sensor. Grand price of €500 to sort it.
 
Well I can confirm that this never happens on the diesel :lol:

Seems normal behaviour to me. The car is relearning its settings. On the old hondas. We'd remove the radio fuse or disconect the battery to force the ecu to relearn. And as said take it for a drive.

Don't know about this HDS procedure. But the man knows his beans.
 
the car will gereraly start its own idle learn procedure although it can be initialised using a hds tester. the same as what cj has menchoned, get the car to full running temp and let it idle on its own for approx 5 to 10 mins.
 
the car will gereraly start its own idle learn procedure although it can be initialised using a hds tester. the same as what cj has menchoned, get the car to full running temp and let it idle on its own for approx 5 to 10 mins.
Thought it was, the same procedure was used on my old Accord. It idled rough for 10 mins or so and then began to pick and smooth its idle itself.

Hope you get it sorted mate and let us know what the outcome is?
 
Is the RPM speed at idle important? From memory mine is about 1500 and I changed the battery on Ne'ers day.
 
Is the RPM speed at idle important? From memory mine is about 1500 and I changed the battery on Ne'ers day.
Is your car running at 1500rpm at idle all the time, even when the engine is warm?

If so I would say there is a problem with your idle speed
 
Mr Sparkle can you give more details on what your car does, Does it constantly idle at 1500 rpm now even if the engine warms up?
 
Be a pretty poor show if the Honda ECU can't relearn settings after a battery disconnection. :(
 
Hi Shabz, I've haven't been paying attention, the thread peaked my interest though. For some reason I seemed to think the idling speed was a bit higher this year than it used to be. However after driving to work and stopped in the car park today it was more like 800rpm. 8am was a long time ago so I forget the exact number, but definately under 1000.

So if it is revving higher at idle, is it a concern? I have a service coming up in a few weeks - maybe I should mention it?
 
do you know what non-volatile memory is?

After working in the electronics industry since leaving school and holding several related qualifications i'm well aware of what non-volatile memory is, thank you very much.


Do you know what a feedback loop is? B)
 
After working in the electronics industry since leaving school and holding several related qualifications i'm well aware of what non-volatile memory is, thank you very much.


Do you know what a feedback loop is? B)

Can we all play. Do you know what a pseudowire is?
 
Guys lets just stick to topic,

Mr Sparkle from what you describe it seems quite normal that. Main thing is whn the car is parked and in neutral with a warm engine then it should be around 800rpm which you say it does. On cold starts the engine does idle higher which is normal as it is trying to warm up quicker.
 
And I am suppose to figure that out by seeing Martin F username the greatest electric spark y in the world am I ? dude you looking for a scrap why dont you start a thread on your own forum.

A bit touchy aren't we? :huh:


You asked a question, I answered it.........simples!


I'm just suprised that the answers on this thread seem to imply that the Honda ECU can't relearn basic settings after a battery disconnection and requires manual calibration using various tools and processes. You could answer that which would be more constructive to the thread rather than posting patronising questions.
 
if yo are so surprised with the comments they why did you intervene with your comments?

Because I was hoping to learn more from those with more knowledge in the world of Honda than me; alas it looks like that will not be the case. :(

It was a rhetorical question to try and ascertain whether the implications in the thread were correct or not.

As you say, move on...
 
Shabz why is 800 normal Ideling for the 2.4 ? the ideling for a 2.4 should be 600±50.
CJ if you read it properly I said around 800 rpm and not exactly 800 rpm. Also Mr Sparkle does not have the exact figure and is just estimating the figure.
 
Ok I have read it ..but forget it ..:lol: its quite normal.
Forgotten already lol

I remember on my old Accord the idle use to dip down and then come back up when the idle valve was dirty, use to drive me crazy lol
 
Well I have always done the rest by the HDS so I cant say for definitively but if you can do the ECU reset the old fashioned way then I suppose you could do it by this procedure

Turn the ignition switch ON (II), and wait for 2 seconds.

Start the engine, and hold it at 3,000 rpm with no load( no air con no radio nothing) until the radiator fan comes on.

Let the engine idle for about 5 minutes with the throttle fully closed

that will do it .

Well, I had been on a long trip after posting, and thought it had solved it. Unfortunately not. So I tried this procedure. I took it to 3000 in neutral, for 3 minutes or so. I couldn't tell if the fan had come on, maybe it didn't, but either way the revs came down to 800 then down to 650! I left the car in idle for 3 minutes or so. On re-ignition the revs started at 1100 then dipped immediately to 900, then slowly dropped to 650 in fluid succession. Job done. So if there was a thumbs up smilie, I'd be using that.

I did actually charge it up in situ before. And as Pepster states, the charging current of these is low, but if in doubt look at the charging instructions of your charger or FAQ on their website. For ctek they specifically state that their chargers work without need to remove batteries, Interestingly they say that they recommended negative to ground rather than battery because:

"All CTEK chargers observe the directives that apply in the EU. All battery chargers whatever the brand must be approved in line with the same standards. Many more basic chargers can cause the battery to emit a significant amount of oxy-hydrogen gas and also generate a spark when connecting. This represents a major risk of injury and it is therefore stipulated that the first terminal should be connected away from the battery in order to reduce the risk. A CTEK charger is spark free, has a minimal amount of gassing and can therefore be connected directly to the battery. However, we do not recommend this for approval reasons." -

Now whether thats marketing talk or whatever, who knows, but I thought that as much as batteries and charging them can be interesting, if at all, its something to be mindful of.

Thanks folks, its worth a discussion and hopefully will help other people if they have idle issues.


Steve
 
my car hasn't blown up to smithereens yet :lol:
[/quote]

I would VERY STRONGLY recommend that if connecting a battery charger, when you connect the second terminal (negative) you DO NOT connect it to the battery!!! As per most manuals they advise to connect it to an earthing point away from the battery. The risk of a battery exploding due to a spark igniting escaping gas from the battery is a very real one!!

I know of a guy who tried to jump start a fork lift truck battery with jump leads connecting them straight to the battery terminals. The battery exploded in his face!! The plastic battery casing splintered taking his eye out and the battery acid burned the skin on his face, chest and arms.

I always connect the battery charger before plugging it in so when I switch it on at the socket I am a safe distance from the car. Many people still connect the charger to the battery after plugging it in, which could potentially cause a spark.

Plus if using jump leads ALWAYS ALWAYS make sure the last (4th) connection you make with the leads is on the car you're taking the charge from and also onto an earthing point away from the battery. That way any spark generated from creating the circuit is away from the battery, but most importantly away from the flat battery.

Complacency with a flat battery I feel is a very dangerous thing. These things are potential bombs and can do you very real damage if you're in the way when they go bang!

Please take care around them.

Matt
 
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