84 pick up sputters

hi guys/gals, have an 84 chev.
it is btwn -20 and + 10 normally here right now, and have changed the starter, fuel pump, plugs, dist cap, coil and rotor. when i try to start the rig, one pump, it will run for a second or two and dies. pump 4-5 more times, wont start. pump about 6-7 times more, hold pedal to floor and the motor will sputter, for a minute or two, emitting brown/grey exhaust smoke, till it clears itself. seems like this is the only way to get it started, and at times even this will not do it. seems like it is not getting enough gas to keep it running. but, once started and runs for a few minutes, it starts again and runs ok. am perplexed. choke is working, and am getting a shot of gas to the carb when the pedal is depressed.
any clues as to what to look for? thanks all

My dad has an 80 scottsdale 1/2 ton and for the last few years that it was still being driven daily in order to get it started you had to pump the snot outta it, i mean 20-30 times for it to start. I have never seen a vehicle require so much fuel to start, it is next to impossible to flood that thing. It has been off the road now for about 5 years but still gets used around the property and in order to start it you have to pump it till the cows come home. Back when it was still in service he did take it in and have it checked just to be told that everything was fine and if pumping it like that did not flood it , to not worry about it. I know none of this helped you in any way , just sharing a similar expierence is all.

Make sure the choke is working, and stepping down once the engine starts. The choke plate should be shut when cranking, and then open once the sngine starts to run. I had the same problem with my 86 Silverado, I thought the choke was working, but it wouldn't shut off. The brown/grey smoke is most likely because it is running VERY rich. Once it gets hot enough, the vacuum probably rises a bit and overcomes the resistance of the vacuum pull-off.

Mine has the quadrajet on it, if yours does too, the pull-off is on the left side. It is a round piece of metal with a vacuum line on the end closest to the front of the engine. To test it, disconnect the vacuum line and linkage. Depress it all the way. Hold your finger over the vacuum port, and release the linkage. It should stay in place. If it moves back at all, replace it.

J-Ri,
thanks for the tip. will try that as soon as the blizzard passes, lol, -30 outside. but it's hard to check the choke as i cant get this beast running most of the time. will check what i can. thanks again.