even if it also should work with combustion engines, I admit changing to TE Dynamos instead, they produce RF instead of MJ energy and that can be transferred with TE conduits.
my setup was to connect power to the back, fill oil from the bottom/top and extract the fuel from bottom/top... worked just fine...
PS: I used the BC Refinery, not the one from the Galacticraft mod (the one from BC is the red one with mostly glass)
the speed of the refinery mostly depends on the amount of power you put in, if the 2 sticks on the front side are moving up and down, it generally works, but they also indicate how fast they are, if they are bright green, thats most output you can get