I was sent to a camray 3 90/130 with a rbl 40g5x burner, customer said she had a delivery more than two weeks ago and it has started to lock out on first demand in the morning. I connected guage to pump and had good continuous pressure, drew off some oil and it was clear, checked electrode setting and spark, changed coil, photo cell and control box, she now reports that it has continued but on occasion it will fire on first demand but lock out on second demand any ideas cheers