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        General >> Problems >> lady owner- revs increase when braking
        
(Message started by: zephy on Nov 15^th, 2004, 2:38pm)

Title: lady owner- revs increase when braking
Post by zephy on Nov 15^th, 2004, 2:38pm

95 M 2.0 ghia 16v ( petrol) Over the past few days I have noticed that the engine revs increase when I need to brake.
This happens everytime I put pressure on the brakes and lasts for approx 3/4 secs then dies back to what is normal for my car (just under 1000)
I've tried to look after this car myself and buy any spare parts I need from ebay!
I have read through the 35 pages of problems listed and smiled at the other faults with my car that many other owners share, like trying to get the shopping out of the boot only to find that I have to crawl into the boot from INSIDE the car to OPEN IT!!

Title: Re: lady owner- revs increase when braking
Post by Eddie on Nov 16^th, 2004, 5:27am

It is possible there is an air leak in the system somewhere, the brakes use inlet suction (vacuum) pressure to operate.Working the brakes is exposing the system to an air leak.

eddie

Title: Re: lady owner- revs increase when braking
Post by zephy on Nov 16^th, 2004, 9:15am

Thanks eddie, I drove the car last night and I noticed that it is not the brakes it seems to be the clutch. I thought it was the brake because I of course I use the brake when changing down a gear. I braked several times with out changing gear and it did not 'rev up'.
But it def. still does it when I engage the clutch to use engine braking.
The gear change though is smooth and no slipping else where no problems engaging any gear??

Title: Re: lady owner- revs increase when braking
Post by Geoff_W on Nov 16^th, 2004, 9:28am

Well depending on the gear you are using for engine braking and the situation you will see the revs increase, sometimes significantly.

When you spotted this as a concern, how much were the revs building up to?

In addition to all the other possibilities, I guess here are some other thoughts, you may have a stiff throttle linkage, sticking cable or perhaps just enough pressure on the accelerator peddle to blip the throttle. (Like when double de-clutching)

Title: Re: lady owner- revs increase when braking
Post by wumpster on Nov 16^th, 2004, 9:31am

i had a problem with my 2.016v reving as you described it was the idle control valve on mine took it off cleaned it in petrol and it has been fine since hop this may help 8)

Title: Re: lady owner- revs increase when braking
Post by SaveTheNight on Nov 16^th, 2004, 10:19pm

could still be vacuum ..doesn't it have vac assisted clutch ?? hmmm .. or maybe im wrong .. I know its assisted though .. someone will know ....STN

Title: Re: lady owner- revs increase when braking
Post by Eric_R on Nov 16^th, 2004, 11:59pm

Zephy,
I think you may have a hanging throttle. Carbon builds up around the throttle plate (butterfly) inside the throttle body, so that when you lift the foot off the accelerator the throttle plate holds open slightly. This lets in slightly more air than the engine needs and causes the revs to increase, at which point the vacuum against the throttle plate pulls it shut, which then drops the revs again.
It's very simply repaired. You need to get inside the throttle body with some carb cleaner - undo the hose from the air cleaner and spray round inside the throttle body and the butterfly valve to dissolve the deposits.

HTH

Title: Re: lady owner- revs increase when braking
Post by Eddie on Nov 17^th, 2004, 3:51am

Methinks Eric just hit the nail on the head! ;)

Having said what I did beforehand,I can vaguely remember a similar problem I had and cleaning the throttle body did the job, DOH! :-[

eddie (the red faced one!)