Chugs while Accelerating

[Invisablerunner]

I have a 77' Chevy 350 with a automatic transmission, I have taken the truck to a couple mechanics and no one can seem to figure my problem out. My truck ran great for a while now every time I attempt to accelerate the truck chugs and seems to lose power. If the truck is in park or neutral I can rev the engine up and hold it wit out any problem. I do have a decent size hole in the exhaust, which I thought may cause that. But I am unsure. Any ideas will be much appreciated.

Eric

[Lt.Del]

check timing
may be bad accelerator pump on carb
if it loses power on acceleration and has problem going uphill or the like, could be bad fuel pump

[1981 ss chevy]

i had a problem similar to this with my 81 i had a cracked vacuum line try checking all vacuum lines and fittings

[Irish_Alley]

i want to say accelerator pump  but before you do take it all apart first check for vacuum leaks. when you rev it in n do you hold it or just rev?

[bobcooter]

I had a problem similar to that on my 79. It would take off fine and then it would start slowing down. It was a dirty fuel filter. I replaced the one in the carb and also put a good sized one between the fuel pump and the carb. No more problems.. I could probably do away with the one inside the carb too..

[VileZambonie]

Start with the basics. Check the cap and rotor, plugs and wires. Clean and adjust the carb. Make sure you have no vacuum leaks. Check for kinked fuel lines and proper fuel volume. What kinda carburetor is it?