Freelander Throttle Sticking

Hi people,

Am new here so apologies if it has been raised before!

My 1998 Freelander 1.8 seems to have developed a sticking throttle.
It all started when the exhaust started blowing which has now been replaced.

On a cold start the engine idles at aroun 1500 RPM but doesn't drop on e the engine has warmed up.
If I rev the engine the revs do not drop down, I have to switch off and restart!

I have checked the throttle linkage which seems fine and sprayed it all with WD40.
I then whilst fiddling pulled of a hose which attaches to the bit that says injection, lots of hissing air and the engine started to idle roughly.
Once I reconnected the hose the revs dropped to what appeared normal.
When the engine was revved the revs dropped once the accelerator was released.
All seemed to be sorted!
However after leaving the engine running for a while (to warm the interior), the revs started to creep up slightly. I revved the engine and the revs didn't drop - basically back to square one.
I pulled the same hose back off as before, lots of hissing and the revs went right up!

What's wrong? Any advice gratefully received

Many thanks

Chris

It's probably the Idle Air Control Valve or iacv for short. They have a habit of clogging over time!!

Give your idle contol valve a clean always first on the check list.......
Its located between the cam cover (the part that says injection on it) and the inlet manifold (Big moulded plastic unit behind the cam cover) get yourself some carburator cleaner and give it a good scrub inside with an old toothbrush........

I had almost exactly the same problem and it tuned out to be the throttle position sensor (also known as a throttle potentiometer). Got one for 30 quid off fleabay - working a treat so far

parnas said:

I had almost exactly the same problem and it tuned out to be the throttle position sensor (also known as a throttle potentiometer). Got one for 30 quid off fleabay - working a treat so far

Click to expand...

Did you have the HDC light come on as well?

No - forgot to mention I'd also replaced the IACV first - oops

(HDC = Hill Decent) :rolly:

I would be checking all the crankcase and cam cover breather pipes for splits/perishing get the engine nice and warm and have a listen for any hissing noises....... If you are tinkering at home another way to diagnose an air leak is to spray some carb cleaner in the vacinty of all the vacuum/breather pipes. If you here a noticable change in engine pitch when spraying the pipes you have pinpinted the leak then to replace the culpret!!!

Thanks all, much appreciated

Have finally had the opportunity to have a look at the Freelander but am confused!
Sorry for being thick but where is the IACV exactly?

Have look at this thread http://www.landyzone.co.uk/lz/f9/2004-throttle-body-46795.html and check out the Rave cd

I have just had very similar happen to my Freelander worked fine this AM but this PM went to go home and it wont drop below 18K which is rather annoying. Do they have a auto choke that sticks if so can you disable the choke in some way to see if it's that causing it?

Duncp73 said:

Did you have the HDC light come on as well?

Click to expand...

My HDL is on as well but has been since I bought the car since it doesn't work would that also be something that may effect it if so why would it only start now?

Chokes are very old fashioned these days. Fuel/air mixture is ECU controlled.

I'm more used to old 80's carburettor and choke engines so that's why I thought it was sticky choke.

Had a look today it could possibly be the Idle Control valve since as your see from the photos with the engine running the engine revs didn't change with it connected or disconnected so I guess it means its died?
Where is the best place to buy a new one?

Well the IACV has started playing up again so wondering where is the best place to buy a new one since nothing comes up when I google it?

Hi check my post about high revs at idle

Thanks for advice but I know its the IACV since it goes back to normal running once taken out and cleaned. Just thought rather than taking it out to clean each time just a fit a newer one.