im putting a 4AGE in my AE86 and i bought an external fuel pump from a place called precision auto electrics, 233 Cantebury Rd, Cantebury. $176, its a bosch and looks pretty good.
im told that a in-tank pump off an AE82 will fit in an AE86 but not sure bout the KE15,
i just went for a new pump coz then you will be sure that it will work.
hope this helps.