1995 Blazer will not start. Replaced fuel pump and fuel injector. Only get 20 psi from new pump to injector. If I prime it, it will run fine and die. Is it the fuel pump regulator? And where is it? ECM perhaps? Scratching my head..

Fuel pressure is too low. 1995 4.3L "W" engine with CMFI, fuel pressure should be 58 to 64psi. There's either a leak or the pump is faulty.