Tickover

[steve91]

Clio Williams 3. Engine runs fine but tickover goes to 1500rpm when run hard.
It starts fine and runs at 1000rpm on choke then when its running warm it drops to 800 to 900 rpm. So far so good. If you then rev engine over about 4500rpm the tickover then settles to 1500.
If you turn the engine off and restart the tickover settles back to 800 until you take the revs over 4500 again.
I don't think its anything to do with the throttle position sensor because if you floor the throttle with the revs low in a high gear and then back off before you get to 4500 rpm it doesn't cause the tickover to go to 1500.

It always resets to 800 rpm tickover after switching off and restarting. When it is ticking over at either 800 or 1500 it is steady at those rates, there is no fluctuation.
Have had it on an old Renault diagnostic computer which showed a temp sensor failure which was changed and the fault code cleared which didn't make any difference.
Any ideas?

[MatBrown]

Road speed sensor on the speedo cable.

[steve91]

I'll replace it thanks

[Chadwick]

Read up on it beforehand. Search other topics. You may be able to solve it with something as simple as an additional Earth.

Al