So I am tired of messing with my truck and AF gauge. I worked on it again last night. The same thing was happening, in driveway 14.7 and take for a drive 13-13.5 sometimes 12. I thought maybe the transfer slots were exposed to much (info from gregski) so I lowered idle speed in the hopes this would create more vacuum and pull power piston in fat section of metering rods (info from rpmerf). I get there and it changes after a drive again. I was getting frustrated and pulled vacuum line from egr and truck hit 14.7 to 15. I took it for a little drive and stayed 14.7 to 15 when stopping at stop signs with egr vacuum line plugeed. The climb up to 2500 is still giving a reading of about 13 to 13.5 though. I mentioned in previous post that when I rebuilt this carb it had a broken off pencil in vent tube, presumably pushing down on power piston. If truck does not pass today I am going to put a pencil back in there
