Howdy, replaced the factory exhaust with 2.5 inch on my 77 trans am I also added a o2 bung out of curiosity, since I KNOW the previous owners were running it very lean (found the APT was bottomed out when doing a rebuild and some other oddities, manifolds basically white in the inside) Seems my idle and WOT are in good numbers, maybe a tad rich low 13s, about where it ended up when using rpm and vacuum guage. My main concern was everything in between. My cruise, part throttle and heavy throttle. Cruise generally is around 16ish, heavy and part throttle can get as high as low 19s until I WOT then it is fine. I also do get excessive lean popping at deceleration especially when down shifting the 4 speed. Letting off the gas quickly at medium rpm’s can hit low 20s but I feel that is normal for the small primaries. Car does run very good no hesitations gets up and goes relatively good despite being a 77 Pontiac 400, at least to me, I do not have a good base line. Just wondering if this is normal for a quadrajet or if something needs to be addressed.
Car and carb is stock everything, rebuilt the carb with a cliff kit a few years back. Unsure of jets rods and all of that but it is all stock for a 17057263 carb# besides what is in the usual cliff rebuild kit, although I believe I have the original power piston spring. Apt is already pretty rich 4ish turns out, brought it out from 3 and it helped a little bit. Curious if anyone has a solution or where I should start I am thinking jets or rods but want to make sure instead of going the wrong direction I can get a carb running good but I’m far from knowledgeable enough to get it perfect. Lemme know if more information is needed as well… thanks
