72 caddy hearse qjet problems

I can post a link to a video of the engine if it helps.

1972 Cadillac Superior hearse. 472ci with Rochester qjet.

Rebuilt the carb last year, new cap, rotor, plugs, wires. Car starts ok and runs fine but if you give it gas in gear, it quits after a sec.

Vacuum valves for choke and distributor are good. Idle vacuum is 17-20. I think this is a fuel issue rather than anything else.

Thoughts?

 

Look down the carb, and move the throttle linkage. You should see the accelerator pump squirt fuel from the discharge nossils. If no fuel you found the problem.

 

When you rebuilt the carb did you alter the spring tension of the secondary air valve?

 

Or... possibly the vac. advance is connected to manifold vacuum when a ported source would be better..? Ported vacuum would help prevent a loss of vac. signal to the vacuum advance, when the car is in gear and you first start to open the throttle.

 

The air valve opening up too quick could be an issue or if those few seconds get you half way across an intersection and it falls on it's face and after you let up for a few seconds it will go again you could have a fuel delivery restriction.

 

You did put the checkball back in for the accelerator pump?

 

The local FLAPS carb kits include accelerater pumps that are supposed to be OK in this new fuel we have. Lots of times it only takes a short while for the pumps to swell up and not work any more.
Pull the air cleaner and with it NOT running give the trottle a couple pulls while looking down the top of carb. Should have good strong squirts of gas from the acc pump.

 

Does it still have points ?

 

Is it better warmed up or same as cold start? Choke to lean? Or accelerater pump like the others have said.