High engine idle....like 2,000 rpm

[Willy 2]

Some help needed please guys.

Just recently got the car on the road, mot'd it yesterday. The thing is once the engine is warm having driven it around the block, the revs raise to circa 2k and i cant stop it. Blipping the throttle hoping they'll come down doesnt cure it. The only thing to do is to turn the engine off and start it up again. For some reason this makes it idle back at 900rpm.

This is a repeat process if i go and drive off anywhere.

Im concerned that i might have left of a vacume hose or something. As i have very recently had the hole engine out for its new box, and belts etc.

Has anyone had any experience of this?

I checked the connections of the throttle body but everything seems ok.

What shall i do? At least i've got no chance of stalling now! Almost the perfect gettaway! :lol:

[MatBrown]

Speedo cable.



Mat.

[Willy 2]

I dont think it is. Its nearly wound all the way in. Besides why if you switched the engine off qand back on again would it reset its idle back to 900?

Im :?

[VIPERONE]

definitely 100% the speedo cable.. a rather simple fix.

dash off.... look at the speedo cable.. near the top is a connector that clips in to the cable.. three wires.. splice in to the black wire and earth it on to a screw with a length of wire.. dash on problem resolved.

problem not resolved? replace speedo cable.

[Daz]

I've had this on both my Williams.. and it's the sensor usually in the speed cable block at the end behind the clocks.

Either it's not earthed well or the sensor is damaged (not in place, etc..)

Easy to fix as gunnergibson said.,

[Andyvalver]

Every ****er has these problems, including me lol. I dont think anybody ever actually finds out waht causes it, they just fix it by accident :P

[VIPERONE]

had the prob on my 16 and hybrid

[Andyvalver]

Lol, i bet you changed a few things and they did nothin, and then one day it cured its self. That always seems to happen to me :cry:

[VIPERONE]

nah changed the iscv.. still did it then got the miracle cure from doctor hillpower.

[wilyolddave]

Deffo speedo cable, mine was doing this a month ago!!Did the earthing bit which didnt work ! Then changed speedo cable and hey presto sorted !!!!!!! 8) Was lucky and got a brand new cable of someone on here(cheers mate!) for £20!!

[Itsme]

My car has exactly the same problem apparently its the idle conrol valve sticking
Phil

[wilyolddave]

Hi itsme i was originally told ISCV but if it sorts itself out when you switch off and then back on again I reckon its the cable. Does it only do it when youve gone over 70ishmph thats how mine would start ticking over at about 1500rpm. :x

[Itsme]

Hi
dont really matter about speed just how much i rev engine if i drive it really slowly or just cruise around dont happen.
Yeah and when turn engine of and on again its sorted so it is cable then
Phil

[VIPERONE]

yup 100% cable.

if the earth fix doesnt do it your cable is shaggerood

[Craig]

the road speed sensor on the cable doesnt sense that your coming to a stop, and what happens is when your moving, and the car knows your moving, the revs dont drop all the way to idle (as theres no need)

i earthed mine and it sorted it!

[big hp]

I had same problem, theres some info here you will find helpfull........

http://www.williamsclio.co.uk/forum/viewtopic.php?t=6030&highlight=iscv+speedo

[Coops]

cheers lads, i got same issue and was happy to let sleepin dogs lie but if its that simple to sort am on the case!!!

love this forum at times i really do..........

tear rolls down cheek

[Willy 2]

Sorry to be dragging this on now.

I fully understand exactly what you guys are saying but the old man is using LOGIC.

He believes that the car was working fine before the engine was taken out, which thus proves that the speedo cable was working 100%.

We take the engine and box out, refit it and now its not working and you guys think its the cable. He doesnt really buy that as he says LOGIC tells you it should work.

I will say though that having another look at it today, where the cable goes into the whit plastic bit that goes into the box you can hold the cable and oull it up and down a good 3/4 to an inch. Should it do this? I cant remember.

The old man says its a mechanical speedo so why should this earthing problem affect it.

Im not arguing with you guys, but you know what dads are like!! :roll:

Any further help would be greatly appreciated.

[Craig]

its not the actual speedo cable mate itself, that is mechanical, but the speedo cable has a road speed sensor on it, which is electrical and requires a good earth to work properly!

i had the exact same prob and earthing it fixed it mate. only a 10-20 minute job, worth a try! :)

[wilyolddave]

Hi mate when i had my problems with the tickover, i rememeber someone(big hp i think?!) saying that often after gearbox/engine out you can then get a problem ?????Try earthing-didnt work for me or get a new cable ......bloody hell its snowing on here or is it to many stellas?? :wink:

[Willy 2]

Thanks again guys. Im tackling this head on tomorrow morning. I have had enough of not knwoing how fast im going.

Cheers.

P.S You lot r now on my xmas card list. Hmmm great.

[MatBrown]

I will say though that having another look at it today, where the cable goes into the whit plastic bit that goes into the box you can hold the cable and pull it up and down a good 3/4 to an inch. Should it do this? I cant remember.



That is not correct, needs pushing in properly.



Mat.

[Willy 2]

Thanks mate. I'll sort it somehow!

[matty]

Other thing that can effect revs is there is a clear rubber cone that throttle cable goes through a bracker and sometimes this little rubber thing can move up teh throttle cable causing more pressure and cable and higher revs.