chevy k20 running issues?

[welder.up99]

So I have an 83 k20 with a 350. Has a quadrajet with electric choke.

Truck for the most part has been running pretty good in the cold up until a few days ago.

Now wheb I get moving down the road, the truck starts to sputter and seize like its gonna die, hard to get it past 30 mph. But it idles fine and when you take your foot out of the gas it wakes back up. First time it did this was after I had been driving for like 15 minutes and now I cant really get anywhere. Starts and idles fine. Runs good moving around the parking lot. But thats it. Anyone got any ideas? 

[dirtydog]

Still got mechical pump

[welder.up99]

Yeah still has the mechanical pump, gonna replace that and check the fuel filter in the carb. Hopefully thatll takw care of it. Will also check for loose carb.

[Hammerlane]

Yep, she's starving for fuel..

Fuel pump volume test (redneck style)
disconnect line @ carb and put it in a beer bottle (empty the bottle first  )
crank motor - bottle should be full or close to it within 10 rev's      P.S. - disconnect your coil first so it dont' start.
if it's not....possible bad pump, possible ice in lines up stream towards the tank.

check filter at the inlet - if you have one of the old hard type filters - replace it w/ an inline.

check needle/seat and float bowl last.  sometimes a stuck needle can be knocked loose by smakin the carb w/ a screw driver handle a couple times.

[welder.up99]

Put a new fuel pump and filter on her, running like a champ now. Thanks for all the input