High Idle with Headlights On

[Bigrig]

Howdy

Another quick one hopefully - whenever I turn the headlights on (normal beam) the engine idles up about 250-300 rpm. If I pull up to a set of lights as an example, I can feel it lurching - drop it into neutral and it heads straight up to 900 plus rpm - turn the headlights off and sure enough, every time it just lowers immediately back to 650 rpm.

Understand that accessories use power and in turn they can cause it to idle up a little, but this has only started a month or so ago, and is a huge rpm jump.

Thoughts and opinions??

Thanks in advance as always!!!!

[the ferret]

does it still idle up when you turn the air con on?

[Sir Roofy]

Maybe your running a bit to much wattage or the alternator might be fatigued

[Bigrig]

Thanks lads - air con kicks it up about 50-75 rpm at full tilt (on high) with lights off. Alternator is only 5 months old and was a new 110 amp Hitachi (bigger than stock unit). Not sure what you mean by running too much wattage mate?? Have Narva driving lights and they were put in about the same time as the alternator.

[Sir Roofy]

Thuoght the globes might have been drawing more power than the alternator could keep up with

[the ferret]

MMMM, the draw from the lights is sending a message somewhere, and this is causing another message to go to the hi idle unit me thinks.

[Bigrig]

MMMM, the draw from the lights is sending a message somewhere, and this is causing another message to go to the hi idle unit me thinks.

All very confusing to me mate!! lol

Just becoming somewhat of an issue - the lurching at lights is reasonably prominent due to the engine wanting to take off being idled up - if I let the foot off the brake in idle, I'd easily climb a hill without touching the accelerator!!! Hmmmm, is that a good thing? I think not!!

[growler2058]

Howdy

Another quick one hopefully - whenever I turn the headlights on (normal beam) the engine idles up about 250-300 rpm. If I pull up to a set of lights as an example, I can feel it lurching - drop it into neutral and it heads straight up to 900 plus rpm - turn the headlights off and sure enough, every time it just lowers immediately back to 650 rpm.

Understand that accessories use power and in turn they can cause it to idle up a little, but this has only started a month or so ago, and is a huge rpm jump.

Thoughts and opinions??

Thanks in advance as always!!!!

Maaate See the lil pedal on the right...... take ur foot off it haahhahahahahahahahahahahah (Vino Night)

[the ferret]

I spose it wouldn't hurt to check all your earths, a bad earth can some times cause all sorts of magical events, mine was a bad earth and when I turned the headlights on, the horn would blow, work that one out!!

[Sir Roofy]

Just out of curiosity disconnect a set of driving lights and see what happens
if the revs drop theres a starting point

[Bigrig]

Maaate See the lil pedal on the right...... take ur foot off it haahhahahahahahahahahahahah (Vino Night)

Ahhhhh!!! F:ck me .. That's sorted it!!

Clown!!! LOL. That will be enough of the Tom foolery - that's my job!!!! lmfao

Being sophisticated this evening and drinking scotch - neat. Yummy!!!

Sooooo ... Back to the problem at hand ... anyone? Anyone at all? "help" (in a little, intimidated voice! lol).

[DX grunt]

I know the answer................

The fermenting alcohol and garlic in your guts, leaks out via the pores in your skin, through the open windows.

The wind catches the fermenting plume and swirls it around the engine, requiring the snorkle to breathe harder.

Basically, you're choking the engine and it needs more air - that's why the revs are up at traffic lights. lol hahahahaha

[growler2058]

Ahhhhh!!! F:ck me .. That's sorted it!!

Clown!!! LOL. That will be enough of the Tom foolery - that's my job!!!! lmfao

Being sophisticated this evening and drinking scotch - neat. Yummy!!!

Sooooo ... Back to the problem at hand ... anyone? Anyone at all? "help" (in a little, intimidated voice! lol).


Lah deee daaaah I'm on clean skins gunna be a good night hahahahahahahahhahahhahahahah

[Bigrig]

Lah deee daaaah I'm on clean skins gunna be a good night hahahahahahahahhahahhahahahah

Saddle up boys, we're all getting ready to ride the night!!!! lmfao!!!!

[Maxhead]

Just out of curiosity disconnect a set of driving lights and see what happens
if the revs drop theres a starting point

Agree, if you take the globes out and it happens, you have a short problem.

Start at the front and work back to see where it is if that makes sense...sorry mate thats the bast I can do in my state!

[Bigrig]

I know the answer................

The fermenting alcohol and garlic in your guts, leaks out via the pores in your skin, through the open windows.

The wind catches the fermenting plume and swirls it around the engine, requiring the snorkle to breathe harder.

Basically, you're choking the engine and it needs more air - that's why the revs are up at traffic lights. lol hahahahaha

An obvious amount of effort has gone into this one Rossco - well done ... bit alas, you fail !!!! LOL

Did you get that a lot on your report cards?? lmfao

[Bigrig]

Agree, if you take the globes out and it happens, you have a short problem.

Start at the front and work back to see where it is if that makes sense...sorry mate thats the bast I can do in my state!

By 'state' I am only assuming you don't mean where you live? LOL!!!

Driving lights? Do you mean spotties? If I disconnect the driving lights (in my mind, driving lights are your normal everyday ... well ... driving lights!! lol), won't that sort of defeat the purpose? That is, no current will be getting drawn and hence the problem shouldn't exist? Or is that what you are saying, if they are disconnected and the problem 'does' still exist, then I have another problem? Apart from the obvious ones!!! LOL

[DX grunt]

An obvious amount of effort has gone into this one Rossco - well done ... bit alas, you fail !!!! LOL

Did you get that a lot on your report cards?? lmfao

I just wanted to see you spray your TapaTalk. lol

[Bigrig]

I just wanted to see you spray your TapaTalk. lol

Thumbs are hammering away a million miles an hour mate!!! lol

[DX grunt]

Thumbs are hammering away a million miles an hour mate!!! lol



I give ya credit bloke. You don't do many typos. lol.

[Finly Owner]

Bloody hell are you reading the solutions to the real problem? You seem to be missing them? I agree enought that, you need to check how much actual draw you are pulling from alternator:

Watts/ driving light
Watts/ headlight
Watts/ in all your Leds
Watts in fridge etc
Air con running?

Deeduct from 110watts supplied, and how much for charging batteries and power to keep motor running is left?

Tim

[YNOT]

Howdy

Another quick one hopefully - whenever I turn the headlights on (normal beam) the engine idles up about 250-300 rpm. If I pull up to a set of lights as an example, I can feel it lurching - drop it into neutral and it heads straight up to 900 plus rpm - turn the headlights off and sure enough, every time it just lowers immediately back to 650 rpm.

Understand that accessories use power and in turn they can cause it to idle up a little, but this has only started a month or so ago, and is a huge rpm jump.

Thoughts and opinions??

Thanks in advance as always!!!!

You've got me scratching my head trying to explain this one!

The problem only started about a month ago, does that time frame coincide with any work on the car or any trips-particularly muddy trips?
Does it make any difference switching between low and high beam and also spotlights on and off?
Does the idle drop back to normal as soon as the headlights are switched off?

Tony

[Bigrig]

You've got me scratching my head trying to explain this one!

The problem only started about a month ago, does that time frame coincide with any work on the car or any trips-particularly muddy trips?
Does it make any difference switching between low and high beam and also spotlights on and off?
Does the idle drop back to normal as soon as the headlights are switched off?

Tony

Have to say mate, I'm glad it's not something really simple that I overlooked!!

Doesn't coincide with any work that I can pinpoint. Doesn't coincide with any trips. I believe it makes no difference if high beam is on (happened on way to Sydney last time on a night run, and used high beam and spotties a lot). Turning spotties off and on does zilch as far as I'm aware, but haven't actually tested this one. Drops back to normal each and every time I turn the headlights off (have even found myself doing this at traffic lights at night etc, just to get it to kick back).

Confusing? And you're smart!! Imagine how I feel!!! LOL

[Finly Owner]

What volts are being produced? I assume you have voltmeter working? Are you running HID bulds or just high watt bulbs? If you have increased bulb watt size, did you run them through extra relay? Is it still earthing correctly?

[Sir Roofy]

have to say mate, i'm glad it's not something really simple that i overlooked!!

Doesn't coincide with any work that i can pinpoint. Doesn't coincide with any trips. I believe it makes no difference if high beam is on (happened on way to sydney last time on a night run, and used high beam and spotties a lot). Turning spotties off and on does zilch as far as i'm aware, but haven't actually tested this one. Drops back to normal each and every time i turn the headlights off (have even found myself doing this at traffic lights at night etc, just to get it to kick back).

Confusing? And you're smart!! Imagine how i feel!!! Lol
night run high beam and spotties on bet its a crook soliniode ,RELAYits ok when cold but plays up when hot

[YNOT]

Have to say mate, I'm glad it's not something really simple that I overlooked!!

Doesn't coincide with any work that I can pinpoint. Doesn't coincide with any trips. I believe it makes no difference if high beam is on (happened on way to Sydney last time on a night run, and used high beam and spotties a lot). Turning spotties off and on does zilch as far as I'm aware, but haven't actually tested this one. Drops back to normal each and every time I turn the headlights off (have even found myself doing this at traffic lights at night etc, just to get it to kick back).

Confusing? And you're smart!! Imagine how I feel!!! LOL

The fact that the fault occurs on low beam would to me eliminate the high power drawer theory (ie, too many accessories overloading the alternator).

There are 2 seperate valves that control the idle, both are mounted on the back of the inlet manifold phlenum chamber. One is the FICD (fast idle control device) which is only there to compensate for the air conditioner loads, this appears to be working normally.
The other valve is the AAC (accessory air control) valve which compensates for all other loads, something is corrupting how this valve operates. It could be something as simple as a bad earth.

Tony

[Bigrig]

The fact that the fault occurs on low beam would to me eliminate the high power drawer theory (ie, too many accessories overloading the alternator).

There are 2 seperate valves that control the idle, both are mounted on the back of the inlet manifold phlenum chamber. One is the FICD (fast idle control device) which is only there to compensate for the air conditioner loads, this appears to be working normally.
The other valve is the AAC (accessory air control) valve which compensates for all other loads, something is corrupting how this valve operates. It could be something as simple as a bad earth.

Tony

Righto - thanks. Funny thing is, the NDS software monitors the FICD and the AAC sensors, and nothing is showing up for either with lights on ...

Bad earth? Wouldn't I have flickering lights at least (on occasion) or something physical/tangible to see for a bad earth issue??

Sorry, not flash with auto electrics .. or mechanics ... or much else ... LOL!!!

[growler2058]

Righto - thanks. Funny thing is, the NDS software monitors the FICD and the AAC sensors, and nothing is showing up for either with lights on ...

Bad earth? Wouldn't I have flickering lights at least (on occasion) or something physical/tangible to see for a bad earth issue??

Sorry, not flash with auto electrics .. or mechanics ... or much else ... LOL!!!

Pretty good with your acronyms tho I have NFI for your RFI hahahahahaha

[YNOT]

Righto - thanks. Funny thing is, the NDS software monitors the FICD and the AAC sensors, and nothing is showing up for either with lights on ...

Bad earth? Wouldn't I have flickering lights at least (on occasion) or something physical/tangible to see for a bad earth issue??
Sorry, not flash with auto electrics .. or mechanics ... or much else ... LOL!!!

Not necessarily.

Tony

[Bigrig]

Not necessarily.

Tony

Then I'm stumped - take it to an auto sparky??

[Finly Owner]

How long ago did the rear light bar go on and the leds in roof lights? Mabe a bad feedback through them although not on, or their wiring at least. worth double checking for an earth problem. I'd be checking earth on headlights and spotties systems first though for weak earth.

[the ferret]

Yeah, I think so, there may be an underlying prob that should be sorted, extra drain on the alternator should only slow the revs, not activate the hi idle module, it's probably something simple.

[Bigrig]

Thanks all - greatly appreciated. Off to the doctor he goes!!

[Chappa]

Really sounds like an bad earth, they do some really crazy things when earths play up. Like last week on my brothers commodore the fuel pump was earthing out through the air con, aircon switch on fuel pump on turn air con off and fuel pump dies.

[Bigrig]

Really sounds like an bad earth, they do some really crazy things when earths play up. Like last week on my brothers commodore the fuel pump was earthing out through the air con, aircon switch on fuel pump on turn air con off and fuel pump dies.

Thanks mate - starting to sound like that's the issue - will get it sussed tomorrow!!

[Bigrig]

Righto - a twist that may assist or may confuse even more. Just did a stop start run all the way home testing out all the above, and the one thing I hadn't done was switch between petrol and gas. On petrol, it seems fine - on gas, it does what I speak of above, idles up to 950-1000rpm!!! Switched it back and forth at least four or five times and same result every time - switch to petrol, run it and pull up, no advance on the idle, switch it to gas and run it, and sure enough, pull up and it's hammering again around 1000rpm. Back to petrol and as pet above and so on - same result each time??

Now I'm really confused - or does that now ring a bell with some of you?? Thanks again in advance!!

[YNOT]

Ahhh, now it all makes sense, this is easy to fix. Drive it on gas during during the day and petrol at night-problem solved!

Tony

[Bigrig]

Ahhh, now it all makes sense, this is easy to fix. Drive it on gas during during the day and petrol at night-problem solved!

Tony

LOL!! Hand on my heart, I was going to post it as a fix - say the same thing as you did, but I thought I'd keep it serious and there's "no way Tony would take the piss out of something this important to me" ... but alas, I underestimated the temptation of easy dunk shots!! LOL!!!

[growler2058]

Righto - a twist that may assist or may confuse even more. Just did a stop start run all the way home testing out all the above, and the one thing I hadn't done was switch between petrol and gas. On petrol, it seems fine - on gas, it does what I speak of above, idles up to 950-1000rpm!!! Switched it back and forth at least four or five times and same result every time - switch to petrol, run it and pull up, no advance on the idle, switch it to gas and run it, and sure enough, pull up and it's hammering again around 1000rpm. Back to petrol and as pet above and so on - same result each time??

Now I'm really confused - or does that now ring a bell with some of you?? Thanks again in advance!!

Yeah that rings a bell.............your really confused hahahahahhahahahahahaa

[Bigrig]

Yeah that rings a bell.............your really confused hahahahahhahahahahahaa

lol - what was the give away?? LMFAO

[growler2058]

Dunno...........takes one to know one I guess........maybe........ i dunno HAHAHHAHAAH

[Bigrig]

Fools rarely differ mate ... so they say!!! lol

[Finly Owner]

Scott, I am no pro but check the gas converter has tight earth wire fitting and all mounting bolts are tight. Check you don't have a worn through wire in the gas circuit..

[boggy2006]

I had a similar problem, but the other way around. For months the engine would idle high long after it was warm, then suddenly when I pressed the brake pedal or switched the lights on it would drop the revs by about 300rpm. Then just as suddenly, both problems fixed themselves! Sorry I can't help, can only say these things have a mind of their own! LOL.

[Bigrig]

Scott, I am no pro but check the gas converter has tight earth wire fitting and all mounting bolts are tight. Check you don't have a worn through wire in the gas circuit..

Will suss it out this morning - thanks!

[Bigrig]

I had a similar problem, but the other way around. For months the engine would idle high long after it was warm, then suddenly when I pressed the brake pedal or switched the lights on it would drop the revs by about 300rpm. Then just as suddenly, both problems fixed themselves! Sorry I can't help, can only say these things have a mind of their own! LOL.

Haha - yeah, thanks for the 'moral' support boss!! lol

One of those niggling little things that in itself is probably not doing any harm more than likely, but left unchecked, who knows??!!

[Bigrig]

Well, I've reduced the problem, but not eliminated it. Took the inlet ducting off and cleaned out the throttle body (Nulon throttle body and carby cleaner). I adjusted the AAC bit by bit until I kept the idle at around 630rpm and now the headlights take it up to about 770rpm - heaps better than before!

That said, still a fault to be found!!! Some piccies below of what I did just for reference - the screw on the AAC is the big chisel tip screw at the back of the manifold directly to the left of the big orange spot centre of the picture - turning it in (clockwise) closes off the airflow on idle, but I couldn't take it any further without affecting the idle with the lights off ...

3471

3472

3473

3474

3475

3476

[the ferret]

I don't spose you could have a vacuum leak Bigrig?, just a thought.

[Bigrig]

I don't spose you could have a vacuum leak Bigrig?, just a thought.

Don't think so mate - checked them when I was under the bonnet - an odd one though!

[Sir Roofy]

Beam me up scotty,still think your overloaded,you must have 100mtrs of wire running thru tank

[Bigrig]

Beam me up scotty,still think your overloaded,you must have 100mtrs of wire running thru tank

lol - nah mate, tested that today - nothing else is running (even had the radio off!) - only does it on normal beam, not parking lights and not if I just hit high beam without the lights on (running high beam and all four spotties).

Even turned everything on except the headlights - air con, radio, UHF, interior lights, entry lights, rear spot lights - and nothing, barely murmured. Turn the headlights on normal beam, and away he goes. Got me stuffed! Time for someone who knows what they're doing to look at it ...

[Sir Roofy]

must be the earth on head lights
good luck mate

[Bigrig]

must be the earth on head lights
good luck mate

Hope so mate - fingers crossed!

[Maxhead]

lol - nah mate, tested that today - nothing else is running (even had the radio off!) - only does it on normal beam, not parking lights and not if I just hit high beam without the lights on (running high beam and all four spotties).

Even turned everything on except the headlights - air con, radio, UHF, interior lights, entry lights, rear spot lights - and nothing, barely murmured. Turn the headlights on normal beam, and away he goes. Got me stuffed! Time for someone who knows what they're doing to look at it ...

I still reckon it could be a short in driving light circuit. It could be shorting to an idle circuit somewhere (not sure of whats there tho) and not necessarily to ground. You've pretty much isolated it to just the driving lights only(not hi or low beam), so pretty much rules out anything mechanical.

Testing it could be tricky as you don't know where the short might be but if you disconnect the current +12 to lights from switch end and just run a temporary wire instead and run it with it swithched on this should tell you if thats the problem....does that make sense??
If the idle is fine with temporary wire then you need to physically follow the existing wires to see where the problem might be.

I could be on the wrong track all together but had a similar issue years ago but it didn't interfere with my idle but the timing. It was a short in my high beam circuit only

EDIT: If this doesn't make sense and you think I rambling then just tell me to shut up and I'll get back in my box....lolol

[Finly Owner]

Are you running HID bulbs or just H3? If H3 pull plugs off bulbs and bulbs out and the reinstall them. IF HIDs check wiring.

Tim

[Bigrig]

I still reckon it could be a short in driving light circuit. It could be shorting to an idle circuit somewhere (not sure of whats there tho) and not necessarily to ground. You've pretty much isolated it to just the driving lights only(not hi or low beam), so pretty much rules out anything mechanical.

Testing it could be tricky as you don't know where the short might be but if you disconnect the current +12 to lights from switch end and just run a temporary wire instead and run it with it swithched on this should tell you if thats the problem....does that make sense??
If the idle is fine with temporary wire then you need to physically follow the existing wires to see where the problem might be.

I could be on the wrong track all together but had a similar issue years ago but it didn't interfere with my idle but the timing. It was a short in my high beam circuit only

EDIT: If this doesn't make sense and you think I rambling then just tell me to shut up and I'll get back in my box....lolol

Thanks champion - a task for today!! As said, it's all pointing at the normal lights, so I'll start the process of elimination with the wiring etc.

[Bigrig]

Are you running HID bulbs or just H3? If H3 pull plugs off bulbs and bulbs out and the reinstall them. IF HIDs check wiring.

Tim

Will be the first thing I do - hopefully the simplest things first may resolve it!! Thanks mate

[my third 256]

you could just adjust the lights down and run on high beam
or put a lowering kit on front ssuspension /or raise rear to get the angle right

[Oggittyboogitty]

Not a vaccum leak somewhere maybe

[Oggittyboogitty]

Sorry about that post, missed other pages of posts, so I too may be rambling, had similar issue but with ac, ended up being small crack in vacume hose, and I mean small.

[Bigrig]

Thanks all - done all I can and it's getting checked today/tomorrow whilst it's in getting the reduction gears.

[Sir Roofy]

your welcome mate hope it gets resolved

[Bigrig]

your welcome mate hope it gets resolved

Me too boss - thanks. One of those niggling things that is just frustrating as it could be twenty different things ... and in testing those things, you mess with something else .... buggers me champion!! Time for someone who knows what they're doing to look at it ....

[Finly Owner]

And he'll say there it is Scott!

[DX grunt]

And he'll say there it is Scott!
within 30 seconds. lol

[Bigrig]

Hopefully!!! LOL. Happy to be a dumb arse, just want it fixed!

[Dhuck]

Hopefully!!! LOL. Happy to be a dumb arse, just want it fixed!

So do I. I don't wish to be stuck on the side of the road in the middle of no-where

[Bigrig]

So do I. I don't wish to be stuck on the side of the road in the middle of no-where

Are we still talking about your car here?? Or just another flashback to your younger 'medi evil' times when records weren't kept??? LOL

[Dhuck]

My car aint going to Rocky and back for a day trip

[Bigrig]

My car aint going to Rocky and back for a day trip

Oh yeah ... forgot about that on Sunday!! He'll be right brother!!! I hope!! LOL

[nowoolies]

my son`s car was doing the same thing
after going through half the car and electrical testing found the earth lead on the battery was the culprit
gave it a good scrub bit of anticorrision lube on the terminals and no more high reving dont understand why it worked that way but all good now

[Bigrig]

my son`s car was doing the same thing
after going through half the car and electrical testing found the earth lead on the battery was the culprit
gave it a good scrub bit of anticorrision lube on the terminals and no more high reving dont understand why it worked that way but all good now

I'll try it - thanks. It is a reasonably new battery though (less than 5 months old), so it's a long shot, but I'll try anything!!