Hi All, The stumbling has returned.. Although this time I started to remove vacuum hoses at idle to see what happened.. turns out that if I remove the vacuum line connecting to what looks to be my pwr valve, engine idle increases and the stumbling goes away - even if I then reduce idle screw. As soon as I put it back on, the stumbling quickly returns. I'm totally stumped as to what this could mean? There's also about 18 inches of vacuum on the line that's trying to pull the pwr valve line.
