I have a new-to-me 3.0 automatic with "rebuilt" Zeniths. The car runs and idles just fine but I cannot get the secondaries to open for love nor money. Nor will it rev over 4200rpms either static or under load. Both secondary diaphragms are good, newish, and free. They both pass the "hold vacuum with finger over little hole" test and secondary butterflies are free... so I'm becoming convinced what I have is a lack of vacuum in the carb body to pull the diaphragms. In both carbs.
Question: Is there an additional source of vacuum for the diaphragms other than the teeny weeny holes in the side of venturis? Is there somewhere I can't see where an incorrect gasket or other leak could deplete that particular vacuum signal and cause the secondaries to remain closed? On both carbs. The teeny holes are open and air passes through to the diaphragm area but cleaning the passages completely requires drilling plugs...
Question #2: Has anyone converted the Zeniths to mechanical secondaries? I've done the 2 barrel Solex on the 2002 with good success but never these.
Question: Is there an additional source of vacuum for the diaphragms other than the teeny weeny holes in the side of venturis? Is there somewhere I can't see where an incorrect gasket or other leak could deplete that particular vacuum signal and cause the secondaries to remain closed? On both carbs. The teeny holes are open and air passes through to the diaphragm area but cleaning the passages completely requires drilling plugs...
Question #2: Has anyone converted the Zeniths to mechanical secondaries? I've done the 2 barrel Solex on the 2002 with good success but never these.