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Mike
Mike, Renault Technician
Category: Renault
Satisfied Customers: 39198
Experience:  Tech Expert
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My Clio, R reg 1.4 Clio revs up on it's own, I have changed

Resolved Question:

My Clio, R reg 1.4 Clio revs up on it's own, I have changed the throttle motor but the fault still occurs. I have an OBD reader and the adapter lead but the reader won't link. When the fault occurs I can see the the motor pushing out the throttle lever, so I believe something is signalling the motor to push out. Have you any ideas on what the fault could be? Neal.
Submitted: 2 years ago.
Category: Renault
Expert:  Mike replied 2 years ago.
Hello Neal and Welcome -

My name is ***** ***** Im happy to help / advise...

Can I first just ask - when you have this fault or while driving , have you had any fault lights on the dash?

Why was the TM replaced - and was the whole TB ( body ) replaced?

Have you had any fault codes out of it at all?

What else has been done / checked etc in a bid to cure this?

|When you say the fault reader wont connect - does it come live / say anything at all?

Too - please give me its Full reg.

Rgds - MIKE..................................
Customer: replied 2 years ago.
Hi Mike, the fault occurs whilst the stationary once the the engine has warmed up, there are no fault lights on the dash. The TM was replaced because I thought it was sticking. The throttle body has not been changed. The code reader goes live but will not link to the vehicle. Nothing else has been done to cure the fault. The registration is R 247 ACV. Regards Neal.
Expert:  Mike replied 2 years ago.
Hi again Neal - Sorry I must have missed you yesterday.

Ok- your symptoms are commensurate with either, an air leak on the inlet side of the engine or, a dirty TB - throttle body causing sticking inside - basically anyway. There can be other causes , such as with sensor issues - but that as above is usual - and the place to start.

Start by a very careful check of the vacuum hoses - check each one for any perishing / splits and / or loose fitting / connections. Check to for any air leaks on the inlet manifold side - inc the gasket of the manifold and the gasket at the base of the TB - shake/ move the TB to see if its loose at all... In any of the above , such un metered air ingress will cause what you have - and as things move by expansion with heat, often its ok again when warmed up..

So you need to work as above Neal - you can use a spray such as wd40 to check joints / gaskets etc - if you spray all around the joints / gaskets seals etc when its doing its tricks... if the engine slows, alters you know you have found it...

A very common cause of this too is the injector seals - pay particular attention to them... again - as the engine is running, wiggle the injectors - each one at a time..if it alters the speed of the engine ( and spray too as above if needed to check )... then you have a bad injector seal... this is very common. Working as above Im sure you will find the issue here and cure it.

Im very pleased to have helped you - Do let me know if you need anything more --

*** Meanwhile - - >>>> Please do click on the "OK/ Excellent ratings" for me - Thank you in advance for that...

You can and are most welcome to get back to me anytime you might need - clicking the OK ratings does not close you out at all..

Kind Rgds, MIKE.
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Customer: replied 2 years ago.
Hi Mike, I have I have checked for leaks on the inlet side & it seems ok. This vehicle has the single point injector system. When the engine is running it ticks over ok until it warms up then suddenly the revs up to nearly full revs, you can see the TM pushing out the throttle lever when this happens. Have you any more thoughts on this fault. Thanks for help, Neal.
Expert:  Mike replied 2 years ago.
Hello again Neal -

Ok - I did wonder which injection system it had but I mentioned that to save time either way..

The fact that you can see the TM operating when it doing this is usually because its trying to sort the revs itself.... Unless an erratic signal is causing that - but I doubt it.

More often than not, this symptom is down to un metered air ingress... As the engine components / sensors etc hot up heat affects them - a common one on this is the inlet manifold / gasket.... make sure you check it when its doing it..make sure you do the "spray " trick as thats the best way. You can also use a length of hose - one end firm in your ear and use the other as a listening device - place it around the gasket for the inlet manifold - and the base of the TB... and all other such areas / pipes etc -- you will hear any leak accentuated through the hose.

The other thing is the TB as I mentioned - check its not loose at all - and carefully check the base for leaks... again - when its hot...

If all is ok - give the TB a thorough clean inside using a spray cleaner - then see how it is.

Im not sure if this has an Air Flow meter - due to the fact that there are several versions / engine codes.... if it has - you could try disconnecting it when it does it - see if that cures it...and then if so, if it then runs ok, thats usually the fault - though the wiring etc should be checked also.

If all else fails you will have to have a plug in diagnostic test done to test the sensors etc... a failing o2 sensor can cause this - but its hard to tell without the proper test on those.. Let me know how you get on..

Best Rgds, MIKE.