Hello, 

Today’s question:

What is the best approach when it comes to the wiring? Do we thin existing spfi harness and overlay old harness or do we splice necessary new wiring into old harness. It looks like most everything is the same except for the distributor/coil wiring and the fuel injection wiring. What else should I be aware of?

If going from an L series to an L series you could reloom the recipient vehicle with the donor vehicle’s wiring loom. 

Otherwise cut down the donor loom to extract the SPFI engine management system. Splice in the necessary wires to get it to work in the donor vehicle, laying the SPFI management over the recipient’s wiring that’s already there. 

Cheers 

Bennie

I choose the first idea.

 

Let the swap begin! My son decided to swap the entire loom. He has every single connection identified and labeled on both ends of both the old and the new harness as well as all of the other mechanical bits. Thanks for the advice.  

I should’ve asked what year each of the L series are. 

Over here mid ‘87 is the crossover from series 1 to series 2. Some cosmetic differences occurred on the exterior, wiring wise the switches for the headlights changed and the cluster switch on the steering column was introduced in the series 2. Some of the dash buttons changed too (flat grey to a black framed with grey insert).

If swapping from a series 1 to a series 2 you’ll have to take these changes with the loom, unless you do some fancy wiring mods. 

All that said, I don’t know if the SPFI came in the series 1.

All the best with it!

Cheers 

Bennie

This is the last plug he is working with. The original harness in the car doesn’t have the corresponding plug, tracing each wire now. Any input is appreciated!

If I'm not mistaken that is the diagnostic test plug. Looks like the one I plug my Snapon scanner into.

Thank you, that makes total sense! He traced each wire and they all went to different systems, we didn’t consider diagnostics. 

Engine bay is clean and ready for reconstruction! First stop, power steering conversion.