kia sportage 2000 blows fuel inj fuse

[philsvwchopshop]

hi
my father in laws kia broke down at the weekend and eventualy the aa guy found the 15a fuse under the bonnet had blown , he changed it the car started and i drove it off the main road to a car park we let it run for 5 mins then shut it off and left it , and the aa man left when we came back and started it up it moved 3 foot and blew the same 15a fuse and the 30a injector fuse,
the kia garage think its the wiring or the ecu and havent realy got a idea , the want £800 to replace the wiring and another £200 for the ecu if the wiring doent fix it , Any one got any good ideas as to what it could be?
as i understand from some of the diagrams on hear the pump/ injectors are all connected to the same fuse ?
Thanks
Phil