Sluggish acceleration on level and very poor power uphill and under load

Engine runs with slightly low idle in neutral, when put into gear idle become a bit rough, engine has sluggish acceleration on level and very poor power uphill and under load. New fuel pump, new fuel filter, rebuilt throttle body, new MAF sensor and housing, new coolant temperature sensor, new right upstream O2 sensor (all to correct OBD1 codes). No CEL, temperatures are good, oil pressure is good. Smoke tested for vacuum leak and found no leak. Fuel pressure tested 35 psi after filter. For all the world it is acting alike a distributor engine with a leak in the vacuum advance line. I am at a loss as to what to do next.