Oldsneverdye

Hello, I have an 80 Regency as a daily driver. 350/4bbl. 55k original miles. I acquired this car for a song back in February. Since then, I have done a complete tune up, motor mounts, water pump, thermostat, egr and catalytic. I took the carb off to change the base gasket 2 weeks ago. While it was off, I tightened all of the screws on the carb and replaced the pcv hose. The car ran the best it ever had. This Sunday, I let it sit all day until evening. I took the family out in it and it stalled leaving the driveway. It's never done this. I started it back up, but it was hesitant. It would only move by going half way into the throttle, and was weak. It wouldn't go over 25 mph wide open. Tonight, I took the carb off, pulled the top off, and cleaned it out. Now it will idle but still has no power at all. I started pulling wires off one by one while it was running, and it made very little difference. The car will take the gas, but it feels "held back" Many of the vacuum hoses are new. I'm at a loss. Anyone have any ideas?

Sugar Bear

Does it run enough to check the ignition timing? Try turning the distributor both directions without touching the clamp. It may have come loose and moved. Check to see if the weights in the distributor are stuck or the vacuum advance is frozen. By removing the distributor cap and twisting the rotor, a spring tension should be felt

When revving the engine does it make any odd noises near the passenger floor as if there is pressure in the exhaust? Try checking for restricted exhaust using a vacuum gauge. The vacuum will decrease significantly as the rpm's are slowly increased.

Pull a couple of spark plugs and do a compression test. If they are low, although it is unlikely at 55K and that it runs at all, the timing chain may have jumped a tooth.

Does the power piston in the carb move freely and return to the top with spring tension? Do the throttle plates open fully using the accelerator pedal?

Had you recently purchased fuel? If you have a gauge test the fuel pump pressure and check the filter.

Is the EGR valve closing all the way?