I’ve bought a engine and have got a wiring loom alongside it the engine I bought is for a wrx sti I wanted to know if the wiring loom I have will plug in or will I have to strip loom and change to the one with engine

 

you don't mention your ,model / age or the donor engine but generally you simply swap all of your ancill's onto the new long engine and everything is as it should be

 

hi mate the current car is a uk2000 gc8 and the donor engine was out of a Subaru forester jdm I have all the wiring loom from the forester but I just wanted to know if I can use the uk2000 loom and join it up I also have the ecu do I Leave the standard uk ecu or do I switch it

 

What year are both cars?

 

The one the engine is going into is a 99 and the one the engine is out of is a 2000-2007 model I was told by the guy I bought the engine of

 

So your ECU will be mappable or can be swapped out for an ECULabs unit. The bit I am unsure on regarding the forrester are the heads. I think they came with AVCS heads but not sure that will be an issue as they won't function with the standard ecu. Alternative solution is take the short engine and mate them to your heads.

 

so as my original post forget anything about the s/hand donor engines wiring loom or inlet manifold and simply reuse all components from your MY00 car
you would need to have the correct JDM 'chipped' keys etc. apart from a ton of other issues that will ensue...........

 

reinstall the Impreza inlet manifold / wiring / ancill's and forget anything other than the bare donor engine..............