Hi. I am Lucas. I have a '73 catalina 2dr with 400 motor, 2gc carb, th375 trans. Car has 72,xxx on it. Car is pretty original but previous owner decided to spray the roof white. When buying the car I noticed the car had a new starter, fuel pump, fuel lines, looked like the ignition had been gone through (however still points), and he had told me the tank has been cleaned. I believed him because it fired up on the first crank. I bought it and took it home. Put on buick rallye's and fresh tires when I noticed the water pump started to leak. Replaced it and the radiator hoses and went on. Drove the car very regularly with very few issues when one day I drove it to school and simply didn't want to fire. Had to have it towed home. Tested the fuel pump and it was getting fuel to the carb. The plugs were sparking too. So I had the carb rebuilt. Now it runs but over half throttle or so it will stumble very bad when trying to return to idle. I rev it up a bit and will bump up to a higher idle that doesn't sound right. I tested for vacuum leaks around carb and found none. Any ideas?

Lucas - I responded to your question in your other thread posting.

Check your fuel filter, points (if they are worn), timing and vacuum advance.

Burn't  rotor or bad cap,  Frosty's suggestions are also right in line.  Good Luck.

Very possible since the tank was cleaned out that it might have picked up residual trash from the fuel lines or maybe even the tank.....Even though the carb was rebuilt...When it is stumbling does it seem like it might be trying to flood..?? stong gas smell??  Running way rich..?? Or is it lean.?? And starving for fuel.??...Very possible could have picked up some trash and gotten stuck in the needle and seat in the carb..One thing you might try..May or may not work...with the engine warm and running...Open the throttle by Hand at the carb to about half way or so...the with your other hand force the choke closed for a couple seconds..then let off the choke and the throttle... allow to idle down...The extra gas forced into the fuel bowl with the choke closed and the throttle open..Sometimes  can float out anything that might be trapped in the needle and seat..But like I said may or may not work...might be worth a try though....

Edited May 31, 20188 yr by TWO LANE BLACK TOP

Thanks for the suggestions guys. Had it running good for a little. Need to check out timing more.

Just be aware...The outer rings on old balancers tend to move around as the rubber deteriorates....Makes setting the timing correctly..Almost impossible.....

Need to find TDC manualy

See if the timing Mark on the damper lines up with zero on the tab...If not Then remark the damper.....To line up with the zero on the timing tab....That will be the  actual TDC.....

Edited July 10, 20187 yr by TWO LANE BLACK TOP