Acceleration Mystery
 

My 240 '86 wagon has a mystery. When first accelerating,
after startup, and before it's really warmed up, it can get either flooded or gas deprived and stall. But it doesn't do this after it has warmed up. One theory presented to me is that the in tank fuel pump has begun malfunctioning and that it could do so on and off as the two brushes wear differently - one more than the other.

But as the above isn't true after it's warmed up - I think it could be something else. Is there something that warms the gas so that when it goes thru the injectors it's vaporized? So that 'cold' gas is causing gas deprivation?

Before it's warmed up and it does stall, I have to actually pump the gas a couple times and leave the pedal down so that as I think the air inlet is wide open. Maybe this is a clue?
Thanks