Fuel Pump voltage? New guy.
Posted: Tue Feb 22, 2011 9:36 pm
I thought I posted this question, but I guess it didn't go through? Anyway, I'm assisting an older couple in the neighborhood with their '81 528i. No start situation. I pulled the CSV, grounded it out, no fuel. I misdiagnosed the problem as being a combo relay at first. I then proceeded to doing the AFM door propped open, turn on the ignition switch and see if you get a fuel pump buzz deal. I checked voltage back at the pump to see what I was getting. I got 8 volts to the connectors on the fuel pump. No noise in the pump at all. I would assume the pump runs off of 12V. But wouldn't 8V carry enough current to at least make it hum a little? Any input is highly appreciated!