You have stated that gas is going into regulator but not coming out of vaporizer, these two items are one in the same, I ***-ume that you have a impco fuel system and if so the fuel lock-off is either electric or vacuum operated so if you have fuel coming out of this device prior to fuel regulator( it will have two hose for coolant and one for fuel supply to carb) than that item should be replaced(fairly inexpesive item) Note: fuel output from regulator will not be a liquid and pressure will be below 7 p.s.i or should be so it is very small amount of pressure. If it is a aisan system pressures should be same to carb, and would be electronically controlled and sould have I.d on parts just like an Impco system would have. Really hate that you are having so much trouble with this unit, truly alot of variables on this problem however if you call a local Toyota dealer they should be able to provide you with a resolution and would be worth the cost of svc call, Good Luck