I just went thru this on my 63 Crown coupe. I replaced the fuel pump, most of the electronics, etc. The problem was in the tank for me. The car started out like yours and got so bad that it stranded me on a regular basis. A cruise around the block became impossible. I ended up dropping the tank, taking it to RENU, and now it runs great. They only charged me $175.00 to do the tank, with me doing the take out and install.