After my 79 350 Auto sits for a week or so, I have to pump the gas several times crank it a few seconds, pump the gas again and then crank it. This usually does the trick. Once it starts it is fine and any time after I crank it, it starts right up. It has new plugs, plug wires, distributor cap, rotor and coil.I suspect the carburator or maybe the fuel pump. I runs fine. Does any one have any ideas?

I don't know much about the internal workings of the carb, but maybe some gas drains back into the gas line or something......or maybe you cap isn't that tight and some moisture is getting onto the rotor. Just guessing. maybe the choke is getting stuck from being in one position for a long time?

Jim,

Quadrajets are famous for "bleeding down" through the bottom of the carb while sitting. This is not necessarily a big problem, rather just a big PITA.

Every Chevy I've owned with a quadrajunk on it did this, in fact, I don't feel comfortable starting a car unless I have to pump it now. If you can bear this, let it ride, but if you feel it's time for a rebuild, by all means, you're not going to break the bank with a carb. rebuild.
Good luck.
Alan

yes the quadrajunk is infamous for this seepage..

you should notice a few puffs of smoke as it starts up after sitting a while, when it disposes of the excess fuel. This actually can have a very bad effect..

you can get cylinder wash.. the fuel runs down the cylinder wall (of the piston on intake stroke) and removes the thin layer oil that prevents the cylinder wall and piston rings from scraping each other.

every quardajunk ive ever owned has done this, even after rebuilding myself and then taking to an "expert" to rebuild.

if its original here is the procedure for fixing this problem.

1 take it off
2 drain the fuel
3 put it on a huge ziplock bag
4 mark it "original vette carb -- do not throw away"
5 put it in your shed.
6 buy a good carb (I like demon carbs)
7 enjoy life

Actually, I have a 600cfm Holly that does the same thing, even after a rebuild. I have just learned to live with it. If it has been sitting for a long time, I disconnect the B+ lead from the distributor and turn it over for a few times before starting it.This not only fills the gas bowls, it also pumps up the oil so you don't get that anoying lifter clatter.

This is easy to cure if the qudra jet is faulty. You do have to take the carb off, and remove the throttle plate from the bottom. There are several soft plugs. The two large ones next to each other are the problem. Clean them off, mix up a bit of JB Weld and coat the plugs. Reassemble the carb and put it back on the car. Problem solved.
Oddly enough, a bad check valve in the fuel pump can cause the same problem. If the fuel is fed from the top it won't bother it. But the Q-Jet supplies fuel from a lower point, and can actually siphon some out of the carb with a bad check valve.

I like Cthulhu's solution myself.