idle valve polarity?

waynos · Post by **waynos** » Sat Feb 16, 2008 6:02 am

ive just managed to get my car running on ms2, but as i have no idle valve at the moment i have had to open the throttle to keep it going. i now want to hook up the vw idle valve (think its made by vdo - has two wires) ive have already changed the parts needed on the ms2 board but i am now stuck.

does anyone know which pin on the valve itself is positive and which is negative? is the polarity important? i dont wanna risk dmaging anything

john.p.clegg · Post by **john.p.clegg** » Sat Feb 16, 2008 6:14 am

Looks like you'll have to find a VW man for the answer but if it is fitted with an internal diode and you connect it the wrong way it's toast....been there done it was that man..
John

waynos · Post by **waynos** » Sun Feb 17, 2008 6:55 am

i dont think it has a diode fitted, been searching the net for ages trying to find the polarity and i cant find nothing!

anyone else have a clue?

turboy · Post by **turboy** » Sun Feb 17, 2008 8:13 am

The polarity isn't important. It's just a coil that gets energized rotating a valve against a spring. If it works in the opposite direction just switch the wires.

Simon

waynos · Post by **waynos** » Sun Feb 17, 2008 8:29 am

excellent, thanks for that mate! in the megamanual it says to install a diode for flyback purposes so once ive found the correct way round to hook up the isv i can put this on

turboy · Post by **turboy** » Tue Feb 19, 2008 9:51 am

The diode is for protecting the switching transistor. Be sure that the kathode side, indicated with a band, is on the +12v side. The valve is then connected parallel to this diode. It's the same setup as with the fuelpump relay...

Simon