Arrived on site to check out the oil furnace that was not operating correctly, upon arrival I replaced the nozzle which was extremely dirty and the pump screen. I readjusted the gap for the electrodes, the existing gap was double the width of what it should be and on cold start may have been causing the spark to drop out and causing a flame failure. I adjusted the z setting as well and confirmed that the combustion head did not have any cracks or was being impeded. Replaced the flue pipe and sealed the chimney, started up the furnace and it ignited smoothly and instantly. I allowed the temperature in the house to go from 64 to 66° and let the thermostat cycle the system off, I allowed it to cool down and then recycled it and confirmed that the furnace is igniting and operating properly.