Idle Speed Problems

[Paul Clio 16v]

Im having idle speed problems on my 16v. The car idles fine untill i give it some "loud pedal" (as my mate would say), ie. full throttle over 4500rpm. Then the idle sits at around 1500rpm and will not come down unless i restart the engine.

Thing is about 1/2 an hour before this started my speedo cable broke. The speedo as far as i can see is completly mechanical and shouldnt effect anything engine management wise, unless theres some sort of speed sensor somewhere. Cant see it having one though as theres no fuel computer or anything.

Anyone got any ideas or has anyone had similar problems

 

[MarkLD]

From what I remember there is a speed sensor on the cable just behind the speedo which I assume the ECU takes data from, so that could be your problem

 

[Adams_16v]

yeah, if ur speedo cable bust then thats the reason! it senses when ur moving so to keep the revs up longer when you put the clutch in to change gear!

 

[Paul Clio 16v]

Yeah but if the speedos dead then it assumes the cars not moving.

 

[steve a]

Its the speedo cable mate, mine does it but i havent replaced it yet. Not realy it getts the reading before the dials.