I have a Jet Q-jet that's a couple years old. This problem has started this year- when it sits overnight or more I have to pump, pump, pump, to get it to fire as I crank, crank, crank. Even in summer weather it does it.

The choke is getting voltage, and when you turn on the ignition and press the accelerator down it does set the choke and fast idle.

Now I have to check but it seems the bowl is draining out when it sits. I haven't had this problem with a carb in the past.

Also- looking directly at the choke from the passenger's side fender, do I loosen the screws and turn it clockwise to richen, and opposite to lean the adjustment?

 

Sounds like a fault in the ignition system to me. Weak coil, etc.

 

If the bowls do empty over time, check your fuel filter (assuming stock inlet type). It should have a small rubber check valve in it, preventing fuel from draining back.

 

There are well plugs on the underneath side of the main body that are known to leak. You have to remove the carb to see them, and it's easiest to get to them if you remove the throttle plate from the main body. They are exposed directly to the intake manifold when mounted on the engine, and sit at the very bottom of the fuel bowl. If they leak, they drain the fuel bowl if the car sits long enough.

 

Well I have an update- I checked after it sat for three days- I turned on the key and set the choke. Then I pulled the air cleaner off and flipped open the choke flap with my finger, and pumped the throttle with my hand- I got a nice shot of fuel from the accelerator pump squirters- in fact it shot each time I pumped.

I do think this may be an ignition related problem.

What would cause it to have to crank like this for 30- 50 seconds cold before firing? Weak pickup coil?

When it's warm you just have to breathe on the key and it starts right up and idles.

Igniton is a stock vaccum advance HEI with a farly new AC delco module- the cap, rotor and coil all look good.