Ran out of oil, refilled, push red buton does not fire?

I have a TURCON TROJAN oil fired boiler with a STERLING 40 burner. Ran out of oil. refilled. Bled the burner, oil comes out , no air but wont fire up. Its about 150 feet from the tank. Boiler was serviced in summer. keep bleed nipple open when i push red button but it clicks just as the oil starts coming out. HELP