Re: Q-jet problem
 

I had an 88 P 30 chassis m/h that came with the 86 Q jet engine.
Had dual air pumps but no cat/cons.
It was very lean from the factory. I had to richen it up to pull a trailer up a hill.
Problem then was, I had to lean it out every year for the E-check money grab.
My point here is it could be lean if all original .But being apart at least twice..no telling. That's why i asked about the idle caps.
I agree. Start all over with the right kit and some research as to what it came with.
Good luck , Mr louis chevrolet, if you ever return

Re: Q-jet problem
 

That?s a sweet truck you?ve got! If it?s running rich at idle, it might be worth checking the float level or adjusting those idle mixture screws. I?ve had a similar issue with an old pickup, and sometimes a vacuum leak can also mess with the mixture. If you haven?t already, a good tune-up could help too. You might also want to connect with a local car club or find a classic car forum; there are usually folks who love helping out with these kinds of issues.