So again, have you checked fuel pressure with a gauge ? And did you change the filter when you changed the pump ? Vortec engines require at least 65-70psi to start and run. Some aftermarket pumps are not up to the task. So again, have you checked fuel pressure with a gauge ? And did you change the filter when you changed the pump ? Vortec engines require at least 65-70psi to start and run. Some aftermarket pumps are not up to the task.

And just for the record, code 138 is not really connected to the fuel pump. And just for the record, code 138 is not really connected to the fuel pump.