I have a 77 datsun 620 that I have replaced a bunch of parts on I replaced the original carb on it with a rebuilt hitachi due to the throttle shafts being out of round and leaking fuel into the manifold. I haven't been able to get it to idle correctly it idles at 1100 rpm and won't respond to any carb adjustments. I recently adjusted the valves and have been checking for any vacuum leaks all to no avail. I wanna know if there is any tips to try and the correct adjustments to the advance on the carb as the manuals I have don't really help. I am almost to the point where I wanna put a L16 intake on it without all the emissions stuff on it. It sucks cause i live in CA and need it to pass smog to get tags and be able to drive it. any help would be appreciated I am to the point where I needs to get it fixed or I will just sell it and later get a pre 75 so as not to have to deal with all the smog BS.

If you are sure you have an air leak then try locating it with starting fluid.

I would personally buy an L16 mani to run and save the L20 nami for the DEQ season.

thanks I will try that. I have seen other 620's without all the smog equipment on 76 and later truck and I wonder if the smog techs would be able to tell the difference. There are so many vacuum lines and all the diagrams I have been able to get my hands on are hard to read and understand I have just done the best I can but could be missing something somewhere.