I am stumped with a nagging problem. I have a 77 CJ7 with the original 304/TH 400 and a D300 added to replace Quadratrac. The previous owner replaced the carb with an electric choke Motorcraft. My problem started a few weeks ago when taking off from a cold start. I would get about ¼ mile down the road and the engine would sputter. As time progressed it would sputter and then stall. It would take several minutes before it would re-start. When I would open the butterfly I would see smoke coming up out of the carb. I tried allowing more warm up time but this doesn’t seem to make any difference. Weather has been all types wet, dry, cool, and warm. After a couple of weeks trying to trouble shoot this problem it got worse. It started to sputter after hitting bumps on the road. This progressed to sputtering and then stalling after hitting bumps on the road. Same re-start problem. This may not be an issue but the connections for the EGR off the exhaust manifold are open. They rusted off and are just sitting there exposed. I plan to replace original manifold with a pair of headers next month. Now, to make matters even more confusing, the darn thing runs great when this problem isn’t acting out. Gas mileage is the same crappy 10 MPG, power and torque is unchanged. Any thoughts on where to look or what to do?