Bad Idle

[IH8HSV]

Hi all...

My misses has an AU Falcon. It runs good but when you put the electric windows up or down it makes the revs drop down real low like its going to stall.

Any suggestions on why this could happen.

My guess would be that the alternator is on the way out and cannot cope with the extra power to supply both the electric windows and spark to the motor.

Although it doesn't do it when the head lights are on. :

Any suggestions please???

Cheers.

[bodes-sh]

i'm assuming you mean by headlights on that the revs don't drop when using the windows with the lights on? easiest way to check is throw a multimeter on the battery while you are using the windows and see how much the voltage drops, that should give you an idea where to start looking.

does it do it all the time, or only sometimes? i would say possibly bad earth. try giving some of the main earth points a good clean and see if that helps.

[IH8HSV]

Originally Posted by bodes-sh

i'm assuming you mean by headlights on that the revs don't drop when using the windows with the lights on? easiest way to check is throw a multimeter on the battery while you are using the windows and see how much the voltage drops, that should give you an idea where to start looking.

does it do it all the time, or only sometimes? i would say possibly bad earth. try giving some of the main earth points a good clean and see if that helps.

Sorry I didnt explain it enough.

It does it weather the head lights are on or off. And yes it always does it.

Its funny how the head lights dont effect the idle, but the electric windows do. Head lights would draw more current then the electric windows.

Cheers.

[Dave_Obsession]

Originally Posted by IH8HSV

Head lights would draw more current then the electric windows.

I would have thought the opposite to be true? Not that I know much about electrics.....

[bodes-sh]

Originally Posted by IH8HSV

Sorry I didnt explain it enough.

It does it weather the head lights are on or off. And yes it always does it.

Its funny how the head lights dont effect the idle, but the electric windows do. Head lights would draw more current then the electric windows.

Cheers.

yep, earths for sure. give them a good clean and it should be sweet

[GS608]

Mines doing the same sort of thing, mainly when its cold, start it up and as soon as it starts the revs drop and it will stall, even if you keep the revs up a bit it will still stall have to turn it off and back on. Doesn't happen all the time. no accessories running or anything

[webby_191189]

Originally Posted by XR-CHIEF

Mines doing the same sort of thing, mainly when its cold, start it up and as soon as it starts the revs drop and it will stall, even if you keep the revs up a bit it will still stall have to turn it off and back on. Doesn't happen all the time. no accessories running or anything

That sounds more lik a leaking inlet manifold gasket. hard to start, rough idle, hunts for idle when you first start it. I replaced mine on sat and found the old one was cracked. Now is a lot easier to start

Also elec window do require a fair bit of power to run

[bodes-sh]

Originally Posted by XR-CHIEF

Mines doing the same sort of thing, mainly when its cold, start it up and as soon as it starts the revs drop and it will stall, even if you keep the revs up a bit it will still stall have to turn it off and back on. Doesn't happen all the time. no accessories running or anything

clean out the idle sped controller, the round cylinder thing on top of the throttle body. if you can give it a good clean with carby or brake cleaner and then blow it out with compressed air. then give it a spray with wd40, or similar or silicon lubricant. should fix the problem. mine was doing this, did the above and hasn't had any probs for the past 12 months or so now.

good luck

[GK]

Originally Posted by bodes-sh

clean out the idle sped controller, the round cylinder thing on top of the throttle body. if you can give it a good clean with carby or brake cleaner and then blow it out with compressed air. then give it a spray with wd40, or similar or silicon lubricant. should fix the problem. mine was doing this, did the above and hasn't had any probs for the past 12 months or so now.

good luck

I'd also start there. It won't cost you anything apart from a can of carby cleaner and a few minutes of your time.

Cleaning ISC Valve
http://www.fordforums.com.au/showpos...9&postcount=43

Let us know if that works.

GK

[IH8HSV]

O.K. thanks.

Ive started doing the earthing points, and will do this ISC valve clean out tomorrow. Hope this solves the problem.


Also while on this note, my BA has a funny idle too. Does the BA have the same ISC set up? It may also do with a clean.

Cheers.

[IH8HSV]

Hi all,

I just wanted to bump this thread.

The bad idle seems to occur when using electrical power. e.g., power windows, brake lights, heater e.t.c.

Is there any testing I can do? Or has anyone else had the same problem?

Cheers.

[FGII-XR6]

bad earths! you need to check all earth connections under the bonnet and under the dask

[IH8HSV]

O.K. thanks fellas.

What earthing points should I pay particular attention to? I know there are the ones on the battery.

Cheers.

[bodes-sh]

Originally Posted by IH8HSV

O.K. thanks fellas.

What earthing points should I pay particular attention to? I know there are the ones on the battery.

Cheers.

there should also be a few up under the dash, this is more likely where the power windows will ground to. just look for wires that are bolted through the body of the car and check for loose ones. you can also pull them off and wire brush/sand back the area a bit to get better contact. good luck

[vbomber]

I have exact same problem it even happens when I switch the headlights on as well sometimes

[bodes-sh]

have you cleaned many of the earths yet? it's either loading up the main earth too much or the alternator can't keep up with the demand. you can stick a multimeter on it, although this won't tell you the amps it's putting out, it will give you the voltage. hold it on the battery terminals, at idle with only the engine running it should be 14.6-14.8v. then get someone to use the windows, heater, whatever, and see how much it drops. if it gets below 13v it's time for either a new alternator or new brushes in it.

good luck

[IH8HSV]

Originally Posted by bodes-sh

have you cleaned many of the earths yet? it's either loading up the main earth too much or the alternator can't keep up with the demand. you can stick a multimeter on it, although this won't tell you the amps it's putting out, it will give you the voltage. hold it on the battery terminals, at idle with only the engine running it should be 14.6-14.8v. then get someone to use the windows, heater, whatever, and see how much it drops. if it gets below 13v it's time for either a new alternator or new brushes in it.

good luck

Hi bodes-sh,

I put my multi meter across the battery terminals today and got the misses to activate the windows e.t.c. It stayed the same at around 14 volts.

I cleaned the earth terminals on the battery. But not too sure where all the other earth terminals are.

Cheers.

[IH8HSV]

O.K....

Today I cleaned the I.C.S, and reset the E.C.U along with resetting the base idle as described on the forum. Also, as suggested sprayed WD40 around the inlet manifold to check for leaks.

This hasn't worked.

However I have noticed that it is when you turn the steering wheel at low speeds ( e.g. in a parking lot or intersection ) this is when the revs die down.

Anymore suggestions? :togo: :togo:

Cheers.

[mik]

i think theres a load sensor on the rack and pinion (look like an oil pressure sender) that has a affect on the idle speed, i have seen it mentioned in post`s past but have no clue wether it would affect your engine that much, it might or it may just be enough load to cause it to play up with something else being the cause, perhaps try disconnecting the sensor and see what happens....let us know what you find.

[bodes-sh]

yep, that's the one. power steering pressure switch.
here's one i prepared earlier (the thing with the blue plug in it):

not that expensive, but a pain to replace. some people chop the ring end off a 12mm spanner to give them a short version that fits onto the nut under that big round metal bit. good luck

[GK]

PM JC, he's done one recently.

GK

[IH8HSV]

O.K. Thanks.

I will try this today.

Cheers.

[Stav]

Matt..clean your throttle body.Remove the sucker and clean the throttle plates. If that doesnt work change your spark plugs.

[IH8HSV]

Originally Posted by Stav

Matt..clean your throttle body.Remove the sucker and clean the throttle plates. If that doesnt work change your spark plugs.

Thanks for the tip.

I did exactly this today. Taking the whole throttle body off is definitely the proper way to clean it.

Is was fully gummed up. It now makes me realise that when you clean the throttle body with a rag while it is still bolted on the manifold, how much is actually missed.

I fully recommend cleaning it this way. It came up brand new, including all the ports to the ICS, butterfly and the ICS itself.

It has made a noticeable difference. It is idling much better. Still a little rough when you turn the steering while stopped but I'm happy with it.

I didn't set the base idle, so maybe if I do this it may come up even better.

--- To set the base idle again would it hurt for me to activate the steering for the 4 Min's instead of the usual way you set it? I thought it may sort out my problem better.

Cheers.

[Stav]

Matt .Leave base idle alone buddy. The power steering switch and air conditioning are on a circuit which alters the idle speed when we turn the the steering wheel or turn the ac on. Its controlled via the ecu to idle speed controller.
The reason is that the car revs do drop under the power steering pump literally resisiting the crankshaft via the main front belt.Same as the air conditioning.Otherwise the car would literally turn off when these accesories are turned on Matt..you buddy stav is just a pm away champ How ya been ? Hows the family?

[IH8HSV]

Originally Posted by Stav

Matt .Leave base idle alone buddy. The power steering switch and air conditioning are on a circuit which alters the idle speed when we turn the the steering wheel or turn the ac on. Its controlled via the ecu to idle speed controller.
The reason is that the car revs do drop under the power steering pump literally resisiting the crankshaft via the main front belt.Same as the air conditioning.Otherwise the car would literally turn off when these accesories are turned on Matt..you buddy stav is just a pm away champ How ya been ? Hows the family?

Thanks Stav. So this would explain why the idle lowers when I use the power windows also - the alternator is loading up.

Why do the revs drop so low though when my BA doesn't do that.

Also I disconnected the battery today because I was working on the BEM. Wouldn't this reset the base idle? What should I do when I reconnect the battery? Do the 2 minute a/c on, a/c off e.t.c. to set the idle? Or just leave it and drive normally.

Cheers.

[Stav]

Just drive the car..trust me mate. I feel there may be a bit of a faul with the cars..dont know why though mine is the same.Might just be part of the programming in the ecu not up to scratch? Im not sure to be honest but i do know of these issues.

[bodes-sh]

i will have to check mine out, i haven't really noticed if it does or not, but i don't think it does. although mine doesn't have factory fitted power windows. i got the stuff and fitted them myself. i don't know if this is because i used a different earthing point or what...