sounds like you have pretty much a 4x4 setup there.. the ECU if it is 4x4, will have a red label and reference number IAW048/02 (earlier non-lambda version) or a green label with ref. IAW048/01 (later with lambda version)

The wiring loom you describe is 4x4.

You then really need to know what the Throttle sensor is - either by taking off the throttle body and reading the number, or possibly making some measurements with an electrical multimeter if you are up to that.. ?

If you are unable to reduce the idle speed below 1000rpm with the adjustment screw under the throttle body, it's likely you have an air leak in the inlet manifold/plenum chamber or associated pipework, which is allowing air to bypass the throttle... you need to find that too