Closed loop is nothing to do with ignition, a coilpack generates a stronger spark, and is a wasted spark system firing 1+4 2+3 together.
Closed loop is metrely having a lambda sensor in the exhaust and this reports oxygen content back to the ecu which then adjusts as necessary, it ius read again, reported back to ecu, and goes over and over forming a loop of info reporting and feedback.
This then ensures that the car is always at the figures programmed in.
You can still get ace economy and running without though if set up correctly, depends a lot on what sort of driver you are, and conditions.
tabetha