I have a 2wd 1990 Burb 2500 w/ 350 TBI, TH400. Especially in the mornings, but other times as well, when I crank the burb up, and step on the gas, it wants to stall. I have to feather the throttle a few times, then it goes and all is well. I have swapped out the FPR, it has a new fuel filter...