So I picked up a 1981 Datsun 720 with a z22 engine recently. It starts and idles perfectly fine but won't accelerate without bogging out. I pulled the carb and rebuilt it with the help of a few diy's (I've never worked on a carbureted vehicle). Got it all back together and replaced all the vacuum lines. I'm still having the same issue. I'm noticing if it's idling and I pull the throttle, the secondary isn't opening. If I do it manually with a screw driver or sonething to push it open, it revs perfectly. From what I gathered by pulling this thing apart, the secondary is operated by vacuum from the secondary diaphragm. I had also pulled that apart to check for tears or leaks but it looks fine. And pushing the rod in, it pumps air out the small hole. ANY ideas on what my next step is would be very helpful and appreciated. This is fairly new to me haha