Turned the furnace, the burner started. When the burner started, the cont is set up for 30 seconds pre purge then fuel is introduced. When fuel is introduced, there is up to a 5 sec delay while I was testing. Checked the fuel pump solenoid for power, it gets 124v right away. Checked the transformer, the transformer is getting weak which can cause a delay. If there is too long of a delay, the boiler will start to rumble due to burning off excess oil in the chamber. Also the burner motor is very loud. The bearings are going bad. Recommend replacing the transformer and burner motor.