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Discussion Starter · #1 ·
Hiya all,

I got a 2ltr petrol, '92 Caravelle, and the engine is appaling when cold. Real bad idle (really low idle and cutting out) but when it's warmed up it runs perfect, idles perfect ect.

My garage said I need to start with changing the 'Cold Start/Running Valve' (vw part: 044 906 171)
Apparantly it's £140+vat and takes 5-10 days from homeland Germany.

Is this the right route, coz it's a bit costly if it aint!
 

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I doubt it's the cold start valve, this only throws extra fuel in to help starting when the starter motor is activated.

I suspect the problem is related to the Idle Stablisation Valve (ISV) or the sensors that make it work. The ISV allows air to bypass the throttle to increase the idle speed and the 2l needs it when cold. Mine is hard to start cold when the ISV is disconnected, but when it's warm I can disconnect it without noticing. The ISV can get clogged up with oil/gunge and a good clean with carb cleaner can work wonders.

The other thing I would try changing is the 2pin temp sensor. If this has failed or is disconnected then the ISV won't work. The other thing that needs to be working for the ISV to work is the throttle close switch in the Thottle Position Sensor (TPS). This is more expensive, so I would try cleaning the ISV and replacing the temp sensor (£10) first.

The ISV is the silver cylindrical thing on top of the inlet manifold (that the arrow goes through), with wires going in the right and a hose attached to the left:

 

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Forgot to say, if ISV is working, or trying to work, you can hear it buzzing & feel it vibrating (by putting your hand on it) with the ignition turned on but before you start the engine.
 

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Discussion Starter · #5 ·
Thanks Gills, thats really appreciated- and pictures really help me.

Tomorrow I shall go and have a listen to the ISV thing and let ya know.........................
 

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Thanks Gills

I´ve had that exact same problem for a while now. I changed the sparkplugs cleaned the distributor and even had a proffessional look at the car and he tuned the idle speed and co content for me. It got better but when it´s cold it always runs poorly and the engine shuts off in idle. I´m going to try and clean the ISV and change the sensor when I have the time.

Very helpfull picture I´ll let you know if it works.
 

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£10 TEMP SENSOR.....Do that first....in fact do it every 2 years !!

been thru 2 on mine int he last 3 years. Also the relay mentioned above caused me intermittent problems...I could hear it buzzing inducting a problem..

Keep us updated on how you get on and if you fix it.
 

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Did you get this sorted as mine a the same problem when cold cutouts but when warmed up goes like a dream :* I have fitted a new isv and both temp sensor still no joy
 
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