[T Bird]

Bob
I could be wrong (and often am), but I think it would take a good size vacuum leak to get you to the point where the car won't run for more than a few seconds. My instinct tells me that these carbs have lost their tune-- that is, that the idle mixture and idle air correction screws aren't adjusted properly.

If you succeed in getting it started, try to give it enough throttle to get it off the idle circuits-- say 3000 to 3500 rpm. If it runs there, but won't idle, then I would say that my instinct is probably correct. If so, you need to start with initial settings on the idle mixture screws (out 2.5 turns) and the idle air correction screws (out 1/4 turn) and go from there. Careful when turning those screws in- many an idle mixture screw seat has been ruined by overzealous tightening.

Another thought- if I try to start my car without pumping the gas pedal 3 times, I get the same symptoms that you report --popping, coughing, stumbling and eventually, stopping. The fuel that the accelerator pump provides for initial starting/running is critical. Don't dismiss the importance of testing the accelerator pump delivery. I have found that .75cc per stroke works well. Others suggest .5cc. Indeed, I would check that first before tampering with the idle mixture and air correction settings or removing the carbs from the manifold. I suggest this because you report that the car runs well initailly when you pour gas down each throat.

The best of luck to you.
John