no gas to carb.

[chevyfire43]

I've got an 84 silverado that was once a 6.2 di. I have now conv. it to a 350. it has the saddle bag gas tanks, I drained and cleaned out the drivers side tank and left the other one empty, I put on one of the glass fuel filters right next to the carb. it will run for about 5-10 sec. and then I will see bubbles in the glass filter then it will die. After it dies I have to pump the gas back to the carb. I have replaced the fuel selector switch, fuel pump, even went do electric pump still no luck. the pass. side tank has no gas cap would that make a diff. also what if I just by-passed the pass. side tank. what could this be.

please help.