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General >> Problems >> car runs by itself
(Message started by: huub on Oct 20th, 2008, 7:35pm)

Title: car runs by itself
Post by huub on Oct 20th, 2008, 7:35pm
Hi. Hope anyone can help me.
if I put the drive into D (ghia 2.3) the car starts running without doing anything. (no gas , foot of brake). up to 60 kms per hour. When I pulle the brake the car keeps pulling, first at 2000 rpm, then lowering to 1200 rpm. When I put loose the brake the car starts runnig imediatly again going steady faster.
What can be the problem?
I hope you understand my bad english.
Thank you
Huub
Maastricht
holland
























0

Title: Re: car runs by itself
Post by gozz on Oct 20th, 2008, 8:24pm
Cruise control fault ?
                          GOZZ.

Title: Re: car runs by itself
Post by scorpio_man on Oct 20th, 2008, 9:17pm
hi there

is the revs higher than usual?

is this a new thing/ just started happening?

hth

Title: Re: car runs by itself
Post by huub on Oct 20th, 2008, 10:04pm
Its not the cruise control. revs are varying. Going up to 2000.
Air sensor replaced. not better.
Huub

Title: Re: car runs by itself
Post by scorpio_man on Oct 20th, 2008, 10:12pm
hi there

sounds like you're idle by pass valve is sticking. take it off (2 x 8mm bolts plus 1 electrical connection) and give it a clean out with carb/brake cleaner. add a drop of oil to it and then try it.

hth

Title: Re: car runs by itself
Post by Thunderchild on Oct 21st, 2008, 3:27pm
Got to agree.. sounds like you are drawing air somewhere. The exhaust gasses get very lean so the ECU adds more fuel so the revs go up and so on until the ECU is happy. Stick your head under the bonnet and listen for the hiss of air being drawn in.

HTH

Tc

Title: Re: car runs by itself
Post by workshopboy on Oct 21st, 2008, 3:33pm
Hi
Its either that or the cat has expired and the hot gasses are being fed backwards by the EGR valve and have melted the inside of the plastic manifold undeneath the idle speed control valve causing an open inlet from behind the throttle butterfly causing a very high idle speed.
Andy

Title: Re: car runs by itself
Post by huub on Oct 22nd, 2008, 8:06pm
Today I went to the garage.
They chekked everything. Cat is ok. they say the bypass valve was cleaned (where can I find it). All sensors work well. But the revs stay high, even higher than before.
Now up to 4000 so I cant get the aut. in D. I put the plug out of the airsensor and then the revs go down to 1200 so I can start driving.
According to the garage for 99% the computer is broken.
Which computer and where do I find him?
In Holland there is no compu to obtain.
GHuub

Title: Re: car runs by itself
Post by scorpio_man on Oct 22nd, 2008, 9:26pm
hi there

the idle valve is just behind the throttle body. small cylinder thing.

while you're having a look around the engine bay, give all the engine wiring a good look over.

http://www.fordscorpio.co.uk/dohcloom.htm

hth

Title: Re: car runs by itself
Post by Thunderchild on Oct 22nd, 2008, 9:59pm
You either have a leaking gasket, possibly manifold, or one of the vacuum tubes has a hole or is disconnected. These are classic signs of a car fueling system drawing air beyond the MAF (air sensor).

Tc

Title: Re: car runs by itself
Post by huub on Oct 23rd, 2008, 7:39pm
Sorry , but wich tubes do you mean?
Gr
Huub

Title: Re: car runs by itself
Post by Thunderchild on Oct 23rd, 2008, 9:32pm
There are a number of rubber tubes which are connected to the inlet manifold. These provide a low pressure vacuum due to the flow of air into the engine. The rubber is known to perish and cause the tubes to fail. This allows air to be drawn into the inlet manifold. As a result the mixture becomes lean and this is detected by the engine management system which compensates by injecting more fuel which causes the engine to run faster.

Check all of the tubes which connect to the manifold for leaks... it will sound like a hiss but it is air being drawn in rather than escaping. It could also, as I said be one of the gaskets around the air intake path which is leaking. This is much more difficult to detect as you will not always hear the hissing sound.

HTH

Tc

Title: Re: car runs by itself
Post by scorpio_man on Oct 24th, 2008, 5:34pm
hi there

you can use wd40 to find the leak(s).

start the engine.

use the straw that comes with the can and spray a little around the intake manifold area slowly.

if the revs change when you spray the wd40, then there's a leak in that area.

also spray around the egr valve (mushroom looking thing on the back, righthand of the engine).

be careful as you will be spraying near the hot exhaust manifold.

hth

Title: Re: car runs by itself
Post by huub on Nov 9th, 2008, 10:35am
hi there

Well I did everything you suggest. I tried a new maf, a new bypass valve, I repaired all the bad wires, (there were indeed some). I chequed all the tubes and I spraid a lot of wd 40 around the intake manifold and the egr. Nothing helped.
The I discovered, that when I put my finger on the hole before the butterfly on the air inlet that the revs go down. So I put a metal ring before the butterfly, covering almost the the whole  hole and the revs are now normal. The car runs well, only the first fifteen secons its a bit tricky when the engine is cold.
There must be a lekkage somewhere or there is something wrong inside the throttle.
I will search further and keep you informed
Huub

Title: Re: car runs by itself
Post by Tompion on Nov 9th, 2008, 7:26pm
What hole?
The only hole before the butterfly (filter side) I can think of is where the IAT should be fitted.

Title: Re: car runs by itself
Post by scorpio_man on Nov 9th, 2008, 7:39pm
hi there

any photos?

cheers

Title: Re: car runs by itself
Post by huub on Nov 14th, 2008, 8:12pm
Sorry I dont now what the IAT is. Is it the inlet tube?
Then that it is, where it is fitted on the throttle.
Huub

Title: Re: car runs by itself
Post by Simmo on Nov 15th, 2008, 8:31am
THIS (http://www.fordscorpio.co.uk/iatdata.htm) is the Inlet Air Sensor which is fitted in the air intake tube on the underside.

Title: Re: car runs by itself
Post by huub on Nov 16th, 2008, 1:58pm
I will make a photo.
Can I post this or do I send it to somebody
Huub

Title: Re: car runs by itself
Post by Snoopy on Nov 16th, 2008, 3:36pm
You can post the picture , in a message or post a link to where the picture is stored. but remember this has to be on a web hosting site NOT on your computer.
Photobucket do a free hosting service along with most ISPs . If you have trouble I am sure someone will help out

Title: Re: car runs by itself
Post by scorpio_man on Nov 16th, 2008, 6:09pm
hi there

here's the photos...
http://img.photobucket.com/albums/v521/scorpio_man/scorpio%20bits/DSCF0821.jpg
http://img.photobucket.com/albums/v521/scorpio_man/scorpio%20bits/DSCF0822.jpg

Title: Re: car runs by itself
Post by Tompion on Nov 16th, 2008, 7:15pm
That's the hole to the IACV (Idle Air Control Valve).

I assume you're not running it with the pipework off (the MAF will give the wrong reading if you do).

Title: Re: car runs by itself
Post by huub on Nov 18th, 2008, 7:31pm
Thats right
With the pipe of the car doesnt run at all



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