Post by
fontana dan »
https://forums.nicoclub.com/fontana-dan-u306490.html
Mon Jul 10, 2023 5:20 pm
Thanks for advice 98_Q45. I bought a smoke machine last summer and found a small vacuum leak at the intake plenum gasket. Replaced plenum gasket, PCV valves, spark plugs, cleaned TB/MAF/EGR valve. No more visible leaks from smoke testing but no change in running condition. Both banks run lean at idle. But it doesn't misfire until it warms up.
So far have had trouble checking for the hidden vac leaks. Want to pinch off hose to brake booster and purge valve independently to check source of unmetered air. Also do a cylinder drop test if I can get it warm enough to misfire.