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Author Topic: 8v reving on its own!!  (Read 1131 times)

Offline wrexham mk2

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8v reving on its own!!
« on: 19 November 2007, 16:41 »
I have had my 8v for a month now and it had this problem when i bought it, now its doing me head in and i want it sorted!!

When i start the car up it revs to about 1800 rpm then drops to around 500 rpm then back up and down again before settling at around 800 rpm, it runs fine when driving and does the same again when im at a junction with foot on the clutch, or if i rev it in neutral.

has anyone else had this problem??  Whats causing it??   :undecided: :undecided:

the car is a 1988 (f) 8v gti, think its a digifant but not 100%,

any help at all would be fantastic!!
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Offline takethefifth

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Re: 8v reving on its own!!
« Reply #1 on: 19 November 2007, 16:52 »
Do a search for 'hunting idle' or 'idle problems' and you should get lots of advice.  :smiley:
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Offline wrexham mk2

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Re: 8v reving on its own!!
« Reply #2 on: 19 November 2007, 16:54 »
will try that, cheers
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Offline takethefifth

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Re: 8v reving on its own!!
« Reply #3 on: 19 November 2007, 17:05 »
It's always worth having a search as there is loads of info on here.

Like the saying goes, give a man a fish and he will eat for a day, teach a man to fish and he will eat for a lifetime!  :laugh:
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Offline wrexham mk2

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Re: 8v reving on its own!!
« Reply #4 on: 19 November 2007, 17:20 »
ha seems to be a common problem!! time to get the tools out and thinking cap on tomorrow i think!!

fanx again
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Offline meg1980

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Re: 8v reving on its own!!
« Reply #5 on: 20 November 2007, 12:16 »
Try this first remove idle control valve go by some brake cleaner spray inside of control valve with brake cleaner.Should give you the result you are looking for smooth idle. If this doesnt help once car is running spray brake cleaner over the inlet manifold and vacuum areas of the engine bay if revs rise you have a vacuum leak which will cause so called hunting.Just be careful when spraying the engine with brake cleaner i.e fire.   
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i was told the 020 rod box was supposed to be a strong box,how wrong are they 5 and counting on my mk2. Hopefully the quaiffe box will last.

Offline jimmy1182

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Re: 8v reving on its own!!
« Reply #6 on: 20 November 2007, 12:30 »
i had a similar problem and it turned out to be a hole in the breather pipe on top of the crank housing, the grommit was worn.
so i'd advise checking for a hole in the pipes, may be causing a lack of vacumn.

Good luck  :smiley:
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Offline Organisys

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Re: 8v reving on its own!!
« Reply #7 on: 20 November 2007, 12:48 »
Vacuum leak(s).
Closed throttle switch or it's wiring is knackered.
Idle Valve needs cleaning / replacing.

 :smiley:
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Quote from: Mr Blue on 29 May 2013, 19:15
... it's turned into a fashion show for poofters.

Offline wrexham mk2

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Re: 8v reving on its own!!
« Reply #8 on: 20 November 2007, 16:24 »
thanks again guys  :smiley: :smiley:
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Offline wrexham mk2

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Re: 8v reving on its own!!
« Reply #9 on: 27 November 2007, 17:22 »
just letting you all know how i got on....................

phoned round for a new idle control valve and theyr not cheep!! I didnt fancy paying the price so i headed off to the scrappy, went to 3 different yards in search of what i wanted and they didnt have any golfs!!

so plan c!!  took the car home then took the idle valve off and filled it with engine cleaner and let it stood for ten mins, gave it a good shake then emptied it out before re-fitting, started the car, adjusted the idle speed screw a tiny bit and sorted!!!   :laugh: :laugh:

the car has been problem free now for 5 days!! :smiley:
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