I am an American living in England until the end of the year. I have an '85 Golf GTI and I want to do a 1.8T 20 valve swap however, to import the car to the USA when I leave, it MUST be in it's original form. (Especially the engine) IF I buy a 1.8T lump from a donor car can it be pre-wired so when I get the car imported I can just drop the engine in and "plug and play" the electrics? Thanks in advance!
RubJonny on here actually offers a custom wire loom conversion service, but his services have quite the waitlist. You could alternatively just get the donor and do the swap once you get back. forums.vwvortex.com has a lot of very helpful information for dubbers across the pond.
With a mk1 it is not so simple to do a straight plug and play on the loom. Also for neatness and getting all the lengths correct we prefer to have the car with the motor fitted to wire it up.
mk1 20v wiring is easier than a mk2 I find, as all the lengths are too long if anything so no extenderising required. use the old and new engine looms to get the routing correct, you may have to make a new hole in the scuttle tray depending on the age of the car as early have 1 small hole and 1 large. mk4 ecu loom is in 2 halves, i recommend you keep it this way as if you make your engine loom right you can fit the 2nd half completely unmodified which makes it easier in the future if say it gets damaged and needs a replacement. I'd recommend you research to see what engines are available in the states, because last thing you want is to use an engine which is impossible to get spares for! edit: main thing though, what fusebox does the mk1 have? if its the early ceramic fuse type you'll want to change this as its just not good enough for efi. either get full loom from later mk1 with CE1 fusebox, or go later mk2 ce2. I'd not recommend mk4 fusebox as its much more complicated and a right pain to make it fit into a mk1. plus imo a step backwards from ce2 as its all bundled in 1 big lump unlike ce2 which is nice and modular
