ok, fuel injectors are controlled by the ecu relay, is it still there? its a 53 relay in slot 1. try swapping it for another one if its there, you should have another 53 relay for the horns.
if that doesnt help look in your scuttle tray, there are a couple 2 pin plugs where the interior loom plugs into the ECU loom, they are prone to corrosion as they are not waterproof.