I've got a 72 suburban with what I believe is the factory carb on it, 7042211. I put some fresh gas in it the other day, started it and it ran ok, idles fine, all was well until I hit the highway and got up to speed when it began surging and struggling, pretty clearly starving for fuel mid-range. Carb is stock, so is the truck except for an hei, it has some miles on it but well maintained, I pulled the carb apart, checked the filter, gave it a visual inspection and a cleanup but everything looked fine. Blasted all the passageways and jets with compressed air, etc. Still has the same mid-range starvation problem. I notice while driving with it surging and struggling, if I hold it WOT it will start to smooth out somewhat as the revs increase but its still running lean. Haven't changed anything with the truck since it ran fine, it just sat for a year or two. But I figured if I had missed some sludge in there it would be the idle side with problems. I changed the fuel pump, same issue. Any help would be greatly appreciated thanks! I havent ordered a rebuild kit yet, figured if theres any specific parts I need I would add them on the same order.
