Fuel flow speed in Oil Furnace

andrewwh

Guys, I need some expert info here:

So got a call from mom saying her oil boiler produced a loud bang during startup, after a bit the safety got tripped. I thought this was a delayed iginition; I asked her to turn it off and let me figure it out. Went to her basement and was able to re-produce the bang with smoke. It was delayed ignition indeed. She told me she neglected this for years (maybe 10 years, what?!). Ok, so I told her let me do the basic maintenance: I changed the filter, and ordered the strainer (ran out) plus the nozzle (looked up based on boiler type). I noticed the filter was really bad with sludge all over. After changing, I let the furnace ran for 30 minutes, shut off and re-start. It fired up immediately with no bang.

However, I noticed something - during the filter change I was unable to close up the safety valve between the single fuel line and the filter. I was able to change it with the fuel dripping, however, besides the safety valve I don't feel comfortable with the amount of fuel coming out - I further tested during bleeding after the filter change - it was dripping out from the bleeding port - dripping I mean dripping fast but not anything close to when I changed my own filter.

Her oil take is in the basement where the oil furnace is also. She has only 1/4 of the oil left in the tank. My question:

1. Is this oil flow speed "normal"?
   
2. Will more fuel added from delivery change the oil flow?
   
   

Thanks!