dumb question, fuel valve open (between the two seat) ? be carefull they are three position lever, and depending if you havn t filled your tip tank and may be using(empty) tank ? Tiptanks are horizontale positions, for main tank it must be on verticale position (if your aircraft isn’t equiped of tip tank there must be a off sticker)
(here is my comanche with no tip tanks, and the left tank open)