hey people
i have searched but havnt found anything. my car's idle has run really wierd lately. when the car is in netrual the car will rev up to about 3000rpms and then just fall straight back down to normal. its been doing this more commonly now. its an ef xr6. anyone have any ideas...

It is revving up to 3000rpm then back down then back up again?

Or staying under 1000 from then on?

This might help!
Have a read.
The Idle Speed Controller Valve, or otherwise known as the Idle Air Bypass System, is responsible for maintaining a smooth, and consistent idle, under different Engine Loads, and temperatures.
It does this by allowing a certain amount of air, to bypass the Throttle Body Butterfly, thereby increasing the amount of air entering the engine, under certain conditions, thereby increasing Engine RPM.The Idle speed control valve is controlled by the EEC-V Engine Management system, and is a spring loaded stepped motor, that opens a small valve, that allows air to flow.
It is actually quite common for this valve to get gummed up and slighty jammed, by carbon deposits, oil, and other foreign materials.This is especially the case if an aftermarket air cleaner, that is oil based
(Such as K & N air Filters), as the Oil is slowly sucked in to the Idle speed controller, and slowly blocks off, and jams the air passage and Valve.Symptoms of a jammed, or dirty Idle Speed Controller include, · 1) Poor idle quality in cold temperatures. ·
2) Engine stalling under load (Eg Power steering operation, Air Conditioning, etc), under closed throttle (Idle) conditions. ·
3) Rough Gear changes on Automatics when changing from second, to first gear, (Engine speed surging). ·
4) Engine RPM surging at idle, for no reason. (I.E. Engine increasing RPM to greater than 1000rpm, for no apparent reason).

it revs up to 3000rpm then goes back down to about 900-1000 then it stays there.

yep thats it. so does anyone know how to clean this Idle Speed Controller Valve. is it that silver oval shaped thing in the engine bay. sorry but dont know how to describe it. thanks

hey chris it the ISC sits on top of the inlet manifold, its got an electrical wire coming out the end of it. Its got 2, 10MM bolts holding it down. take it off n clean all the gunk out of it with turps. gimme a buzz if ur havin trouble findin it

it sits ontop of the throttle body, as ^ said, 2 (from memory i think 8mm) bolts, undo them, undo plastic clip, and pull up, then just clean out the holes

carbie cleaner is the best thing to use for cleaning the out the ISC..

3) Rough Gear changes on Automatics when changing from second, to first gear, (Engine speed surging). ·


I get this sometimes in my EB. Sometimes when braking gradually to a stop, it upshifts to 1st at about 13km/h and the idle goes from 800 to about 1000rpm and it seems to sort of push the car and make it harder to stop.
Other times when braking harder to a stop, it doesnt seem to upshift at all and then idles at about 400rpm. Then on take off it will clunk into 1st.

Is liquid degreaser ok to clean the ISC with?

Cleaning the Idle Speed ControllerThe Idle speed controller can be easily cleaned, and is recommended if the above symptoms exist.To remove the Idle Speed controller, you will need an 8mm wrench, or an adjustable wrench.· 1. Disconnect the Electrical Connector, by pulling down on the bottom Plastic latch, on the Bottom of the connector. · 2. Remove the 2 8mm Bolts that hold the Idle Speed Controller in place. · 3. Remove the Idle Speed Controller.

The air passageways need to be cleaned, and this can be achieved with some Turps, and by rubbing the passageways with your finger.Note: Be carefull if you are going to use a rag or such to clean the passageways, as any material that may be left or stuck in the passageways will be sucked in to the engine, causing damage !
With The ISC Valve, the Best thing to do is fill the Passageways with turps, or WD40, then cover the holes, and shake thoroughly, to ensure that both the plunger, and passageways have been cleaned.Note: the liquid will flow through to the Black Breather cap when shaking.
Once the plunger and passage ways have been cleaned, then Dry the assembly, and re-install the ISC on to the Throttle Body.

Dave

Ok to use the same method for cleaning the throttle body?
My PCV busted and I had to drive it for a short period before I could get it fixed so Im thinking it may have sucked some oil into the throttle body.

carby cleaner into the TB will clean that sucker out. just wipe it with a rag first, then turn car on, get someone to hold revs @ about 1,500rpm and just spray carby cleaner in it to clean it out.

okay. firstly thanks for all the help.

i cleaned the isc yesterday. took the car for a drive and i am sad to say the issue got worse. its reving more commonly at netural and even in gear 1. i can tell when its going to rev in neutral as when the clutch is in to change gears its revs much more.

also now the revs wont go further than 1100rpms when in neutral. it will go to about 1300 then down to 1100 then just stay there.

anyone got any more ideas, or should i visit a mechanic

when I sprayed carby cleaner into throttle body my engine idles high now, from cold it will idle 1000rpm, give it light rev and will hold 1500-1700rpm, swapped ISC motor and not change, if I unplug the ISC it idles 1100rpm, any ideas?

i did it the wrong way.... spraying f**k into the T/B then starting the car up... f**k BANG!