LT1 Idle problem solved....
I haven't posted this problem on here, maybe I should have & saved myself some trouble.
Dumb a$$ parts removed to protect the stupid (me).
Anyway a long time ago I read somewhere to use the fuel tank vent line as the return when putting a fuel injected motor in an 80's G body car. Because that line is 5/16" compared to the stock carbed return line of 1/4". So I did, including using that associated line on the sending unit. So I get the motor running & it doesn't idle for crap, nothing I do changes it. Even reprogramming the PCM for the cam didn't make any difference. Well the other night I had it running again & I noticed a puddle of fuel forming on the floor under the gas tank. ^%$# NOW WHAT! So today I take the tank off & turn the pump on & I notice the fuel is coming out around the return junction. So I take it off, take the sending unit out, thinking somehow the line is plugged. Nope, the vent fitting on the sending unit has a restrictor plate in it, a hole about 1/16" is all that is between the returning fuel & the tank. DUH. It wouldn't idle because the fuel pressure is too high because it can't get back into the tank. Fix that & now it idles great.