[flyingtim01]

jb, You're right, I did miss the part in your first post when you said you swapped out your carb for a used one from a garage.

In that case, get the used one rebuilt. The symptoms you describe sound like your garden variety gummed up carb. If you have plenty of power in the higher rpm ranges and no stumbling/hesitation issues, then your secondaries are more than likely functioning correctly. If that carb sat on their shelf for more than 6 months without being used, the fuel in it has probably blocked your primary circuits to some extent.

First, as some have suggested, move your accelerator pump rod to the inner hole on the arm. If it's in the other hole, as yours is, you're going to get too big/too soon of a shot of fuel, and that might be your issue, if you're flooding your carb a little each time you step on it.

Once you do that, try at least tuning it. The Qjet has two mixture screws in the front, sticking out of the throttle plate. 'Factory default' settings for those screws should be 2-2.5 turns out, as a baseline reference. Get the truck to operating temp, make sure the choke is wide open, then start turning one of the mixture screws in very slowly, no more than a 1/4 turn at a time, until you hear the engine start to miss/sputter. Note the position of the screw, then start to slowly turn it back out until you again hear the engine speed change, and note that position. Turn the screw back in until you've reached the middle point between your two limits, and then do it again on the other screw. This isn't the most technical way of doing it, but without a vacuum gauge, it will get you pretty darn close.

If those two things yield no results, then I would say its time to pull that carb apart and rebuild it. Good news is, it doesn't sound like you'll have to fiddle with your secondary spring tension. Put a good kit and a brass float in it. While you're in there, it wouldn't be a bad idea to epoxy the bottom of the float bowl (they have a tendency to leak, emptying your float bowl and making it hard to start) and check the play in your throttle shafts. When they get loose they suck air and wreak havoc with your mixture.