a dude i know who specializes in fords and old vw's told me you could adjust fuel pressure on the wur by tapping this plug (picture) in or out. another bud of mine with an 82 cab with 87 hydro with cis gathered a few of the wur's from a local junkyard (all vw wur's) ran each unadjusted, then adjusted each of them slightly differently. some unmolested wur's seemed to run slightly richer, with a bit more power. with the plug pushed in, the car seemed to have more power, and to blacken the tailpipe. with the plug pushed out, the car seemed a bit more hesitant, but seemed to run cleaner. his initial intention in starting this experiment came from trying to stablilze the idle.
i knocked the pin in slightly (1/16" or so)on my rabbit (84gti w cis) and it seemed more powerful, and also seemed to blacken the tailpipe a bit. any similar experiences, or anyone know exactly what this adjustment does? i havent seen it in books or heard of it here on the vortex.