Scirocco Register

My GTX has started giving some trouble when starting from cold. The revs hunt up and down and invariably it stalls unless you keep giving it some throttle. Once warm , the idle is a bit unsteady, but not anywhere near as bad.

I am wondering if this sounds like a dodgy WUR, or is something else more likely?

Scala suffering the same - improved with a replacement cold start thermo switch Ed.


Similar to this - http://www.ebay.ie/itm/VW-GOLF-JETTA-MK ... Sw7FRWYa0S

Is that definitely the right part you've linked to?

Part number 043906163A they've listed is still available new... For £105!

yep,i got a couple of second hand ones from stevedismantlers on ebay.

Idle screw working it self lose, try adjusting the idle up and see if that makes any difference, the rubber o-ring gets brittle and flat and the car idle speed drops and the idle stability valve is the only thing keeping it running, new o-ring in pence compared to replacing the expensive bit's first?

And also a good idea is to check the fuel pressure. Mine where sputtering and didnt idle well when cold. Then i checked the pressure. almost 0 when cold. Made the wur adjustable and raised the cold pressure to 1,5 bar. Then it starts just fine and the idle is stable.

My gtx was exactly the same. Adjusted the idle and air fuel mix which made it better but it was swapping the warm up reg that cured it

If it starts up OK but then just idles rough, then its less likely to be the thermo switch, and more likely to be fuel pressure / leak / blockage related...

But rather than just guessing and wasting money on parts to swap, borrow a pressure gauge and multimeter to check things are in spec... btw I fixed a similar problem by cleaning out the aux. air valve, and a pressure test showed I needed to renew o-rings in the pressure regulator. You can get service kits for the WUR and metering head btw... you're a clever chap, save yourself some money!

This is a good chart to follow because it suggests the priorities of things to test in order:

Check that the consatena rubber connections are not split.