Originally Posted by 69chevyLWB
thanks for all the help!
it has a brand new distributor in it and the engine as been running before and i didnt change anything besides the carb. pcv is plumbed all plugs checked and distributor working fine. i think that is somthing i did wrong when i rebuilt it. it idles fine sometimes then others wont idle for crap. i have never been able to give it any amount of gas when i am driving or it just falls on its face. you can revv it to the moon when its just sitting in park but with any kind of load it just nosedives.
It sounds like it's way too rich. I say that because you've never mentioned it popping through the carb. Checking the plug color for being too rich should help decide if it is or not, or have someone follow you to see if it blows black smoke from the exhaust when it's acting up- this is also an indication of too rich.
Possibilities if too rich (this isn't everything, just what I could think of in a few minutes sitting here having my first cup. Also some of these will cause a lean condition, but will cause a bog just the same):
Float level too low. Float too heavy from soaking up gas. Wrong float.
Needle and seat sticking or bad. Be sure you didn't hook the needle hook through one of the holes in the float arm
- it is supposed to go on the back of the float cross piece, closest to the PP well.
Power piston stuck full rich or way too strong spring or wrong length spring for your PP.
Primary jetting way to rich- jets too big and/or rods too small. Late rods in early carb casting (rods will be too short).
APT set way too high. What did you set it at, or did you leave it alone from where it was originally?
Plugged air bleeds. Missing, plugged fuel tubes in air horn. Tubes driven in too far. Tubes that are missing altogether or that have fallen out into the fuel bowl.
Secondary air valve spring tension too loose.
Secondary pull off bad.
Secondary rods too small. (See THIS
thread for more on that).
If the castings are warped, wrong gaskets, mismatched parts, etc. they can be the cause of all sorts of problems.
I already mentioned the choke being on and the ignition timing. If the timing is off or the ignition system faulty, it can run for ****, too.