I replaced the valve cover gaskets and intake gaskets on my 1983 suburban that was run after sitting for a year. I timed it and got it running good. After about a week, it died on me and I thought the mechanical fuel pump went out. I replaced it and it fired right up. It started doing this thing where I can drive it fine in the mornings but it will idle for about 2 minutes and die after work, (intermitenly). It then wont start back up until the next morning. It just will stop pulling fuel. I have already confirmed pump is good, tank is not going into a vacuum and filter is good. A fellow tech rebuilt the carb for me and I am sure this is not the issue. For some reason, the pump wont pull fuel till the next day! This is frustrating enough as I am mechanic at a local shop. Can anyone suggest anything? P.S. I pulled the tank down today and verified no blockages or plugged vents. It ran good then acted up.
Oh! this thing is all factory with 78,000 original miles (Quadrajet)