I hope you guys can help me with this. I can't get my carb to idle down.
It is a 17059520, with thinner secondary rods. The rest of the carb is stock. (I didn't put those rods in, picked up the carb already had them in it and haven't got around to tuning it since I've had other issues.)
The carb is on a 72 Chevy truck
1997 roller cam 350
HEI distributor
Aluminum intake
Full length headers (1 5/8")
Turbo 350 transmission
3.07 rear end with 33" tires
The issues started when going above about 3000 rpm. It was leaning out and pinging. Since I haven't had any other issues with the vehicle, I decided to rebuild the carb. I had a carb kit sitting around for it, tore it apart, cleaned everything, swapped a few parts, and put it back together.
While I was in there I found that the float was kind of low (0.5" when it is supposed to be 0.42"-0.375" depending on who you ask). I also found that the power piston was bent and the passenger side was about 7 mm above the carb body while the other side was about 11 mm above. I straightened it and the engine runs better. I also installed some teflon bushings on the throttle shaft. Not quite ready to be reamed out. Everything in the carb was square and didn't find any other issues.
Before the rebuild, the carb would idle down to 500 rpm smoothly. Now I can't get it to drop below 900 in gear. I can get it idle down a little if I force the throttle shaft down a little, but even with the idle screw all the way out it won't go down. I've checked for vacuum leaks, replaced all the hoses, tightened everything down a little more, ensured the choke stuff isn't interfering and nothing seems to work.
Can someone help me here? I'm lost on what to do.
