ZDriver.com - New Member from WA needing some expert advice

Whats up guys. Names Callon, just picked up my second 280z a couple days ago. I had a 77 a couple years ago and kept kicking myself for getting rid of it... so i got a new one. 78 blue 5 speed swap!

Anyways... I usually just stalk forums but I've got a problem and decided to post here since i'm stumped.

Since I got the Z its always been running a little rich, when I looked at it a couple days before owning it, it was running fine- no problems. But in between that and when I got it the previous messed with the idle air screw in hopes to fix a high idle problem he was having (previous owner being a friend of mine). Ever since it has been running a little on the rich side. The high idle problem was quickly resolved with a lube of the throttle linkages but one day the car just got a little worse and started plummeting out pretty thick white smoke.

So far I've replaced the water temp switch because it was in pretty bad shape and they are cheap, i've unplugged the cold start valve in hopes to see if it was just the sensor, I even removed it and ran it without the valve entirely and barely even noticed it leaning out. Its getting spark. I'm planning on checking the pressure tomorrow, its just driving me crazy because it was running fine until the previous owner messed with the idler air switch I forgot to mention that since I've returned it to its 6 1/2 turns out from full rich. I'll keep diagnosing but I wanted to see if anyone on here lives in the greater Bellingham area and could give me a hand or had any ideas of what to check. It seems like something really dumb and easy but its stumping me.

btw I've downloaded the factory service manual and have been poking at the fuel injection section with no real direction... will keep doing research.