I have a 1995 Chevy Blazer LT 4x4 4.3L Vortec engine 268727 miles and it has a "sputtering"? issue. I have replaced the spider injector assembly, the spark plugs and wires, dist. cap and rotor, fuel filter. I had the fuel pump tested and they said that it had good pressure but instead of a slight drop at acc. it would rise slightly. Any help would be appreciated, thank you

 

fuel pressure regulator pushing enough psi? might want to check that as well.