I have a Blazer S 10 model 95, motor Vortec 4.3 LT that had the following problems: irregularity in the RPM; turn off during the march and it didn't start sometimes. The gas pump was changed when finding it low pressure. Now with the new gas pump and the new gas filter, frequently the motor doesn't respond with the correct power when hurrying; it ascends up to 3000 RPM or less and doesn't acquire power or acceleration, but previously it was working correctly and later it works correctly again, although it follows presented irregularity in the RPM. Injectors neither CPI or Nut kit have not been revised. The new gas pump is: AIRTEC NUMBER CATALOG E3270. What can I make? Please help me.