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Model specific boards => Golf mk2 => Topic started by: davidhawkins_78 on 20 September 2004, 09:40

Title: When should the ISV buzz?
Post by: davidhawkins_78 on 20 September 2004, 09:40
Morning peps,

Silly question ... today driving to work my Golf decided to have a funny 30 seconds coughing and spluttering right across the rev range.

I pulled over and stopped turned her off and check under the bonnet to see if anything was amiss - all looked ok, so I started her again and the revs were way to low and the isv seemed not to be buzzing.

I checked the connections on the coolant sensor and ISV itself - no change, no buzzing ???

I left the ISV unplugged just in case and drove fine - but after arriving at work I had another peak only to find the plug had landed on the exhaust manifold and melted an ickle bit grrrrrrr.? :o

After some jiggling with a Stanley blade the plug now fits - but the ISV doesn't buzz with the ignition on - I can't really tell with the engine running either.

Should it buzz with just the ignition on?? Also, disconnecting the coolant sensor whilst the engine is running doesn't drop the revs, so I'm still suspicious, but the engine was warm.

I've checked all the connections fuses etc so I'm suspecting a faulty ISV ... any help / comments would be gr8.
Title: Re: When should the ISV buzz?
Post by: Blue MK2 on 20 September 2004, 09:43
yaeh with ignition on
Title: Re: When should the ISV buzz?
Post by: Overseer on 20 September 2004, 09:50
yeah it should buzz with the ignition on.

i had a suspected ISV prob last week (luckily for me it turned out its not gone..) 'performance driven' (vw specialists) had some kit to clean the ISV out. he also said something about giving it 12v to test it.  he said a lot of gunk came out of mine. (but he also said that he flushed something else, i think the hose that plugs into it)

i know if you take the whole ISV off you can try to squirt some carb cleaner through it.

hope this helps.  and hope its not the ISV.. not cheap..  :'(
Title: Re: When should the ISV buzz?
Post by: davidhawkins_78 on 20 September 2004, 10:00
It has been a while since I cleaned it, so worth another look at that I guess.

I'll be dam suprised if it's just packed up though - grrrr.

Mine due this is the first thing to go wrong in the close to 2 years I had her, so i shouldn't really complain!

I suppose I should really stick a voltmeter across the ISV plug to check it's getting a feed before trying to find a replacement. Anyone know the voltage it should be getting - I'm assuming from Overseer's comment it's not a straight 12 volts !
Title: Re: When should the ISV buzz?
Post by: benjam_in on 20 September 2004, 10:28
mine hasnt worked for over a year! lol
Title: Re: When should the ISV buzz?
Post by: Blue MK2 on 20 September 2004, 10:28
if you need a replacement, ive got one for you so your alrite ;)
Title: Re: When should the ISV buzz?
Post by: davidhawkins_78 on 20 September 2004, 10:51
Cheers blue you're a star !!  ;D

If I do need it what do you want for it ??
Title: Re: When should the ISV buzz?
Post by: Gambit on 20 September 2004, 11:36
sounds more like the coolant sensor is at fault. ISV's dont usually fail

are you able to switch the blue & black coolant sensors around to see if the ISV buzzes with the ignition on?

i do something similar on 16v's to test the ISV but dont know if u can swap them on 8v's
Title: Re: When should the ISV buzz?
Post by: davidhawkins_78 on 20 September 2004, 11:52
Yeah I must say a straight failure is pretty weird ...

Well I've give the ISV a clean and get the ammeter on the coolant sensor see what we find.

As for swapping the plugs over I'm not sure. That black plug on my car has never wanted to budge either !!!

I'm guessing the black plug puts out a straight voltage and not a variable one???
Title: Re: When should the ISV buzz?
Post by: Gambit on 20 September 2004, 12:42
i assumed one was for the dash & the other for the ecu

are the senders actual different colours or just the cap's?

senders are a lot cheaper to replace than an ISV
Title: Re: When should the ISV buzz?
Post by: davidhawkins_78 on 20 September 2004, 12:54
Sounds sensible to me ... and if it's a dodgy sender i'll be over the moon - I had no idea a new one was over ?200 + VAT from VW :o

Title: Re: When should the ISV buzz?
Post by: Veedubgt18v on 20 September 2004, 22:52
blue temp sender is the ecu temp sensor and the black one does the temp gauge on the dash. they are about 13 quid from the stealership
Title: Re: When should the ISV buzz?
Post by: Gambit on 21 September 2004, 10:35
blue temp sender is the ecu temp sensor and the black one does the temp gauge on the dash. they are about 13 quid from the stealership

yeah but can they be swapped around in order to test for a dodgy sender?