2000 Blazer - Idle only
 

try to make long story short - Blazer overheated, cracked head! Got a used head, machine shop magnafluxed, valve job, seals, surfaced. Replaced all hoses, plugs, wires, cap&rotor. Ran good for 2 days, maybe 20 miles total. Drove today, little longer distance, died at idle. barely made it home, now the engine dies with any accelerator! Off idle, dies, With every 4-5 attempt, I can rev it over 2K rpms, it will keep running, but dies, as soon as you reduce rpm. I checked EGR valve-working fine, not that dirty, checked fuel pressure, looked fine (replaced pump and regulator about 4 months ago). Appreciate any ideas!!

what did the fuel pressure read at key on,and after 10 min of holding pressure?

fuel pressure sat at 55 psi in off position, 65 cranking

Guess we need the codes read then

452 and 453, I had these occasionally before