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Tue Aug 19, 2025 7:59 pm

I have a Mexi Beetle with the Digifant EFI system. The system controls both the fuel delivery AND the ignition timing. Unfortunately my wiring harness has suffered multiple "interventions" and shorts and is pretty much trashed. Of the 20 months I've owned it, it's been running about 8!

Picked up the J-Bugs carb kit and thinking I'll go that route. Have a NOS SVDA Dizzy to go along with it.

If anyone else has done this on a Mexi - would appreciate any advice, pitfalls, etc.

Not that I dislike EFI! When it worked - it was great. Had a L-Jet 79 Bus for 20yrs, EZ to diagnose and repair, no issues. But frustrated trying to trace electrical gremlins thru 30 yrs of abuse in the wiring AND - needing software to set timing, etc, isn't really why I dig AC VW's.

Any tips/advice/sarcasm/abuse welcome.

Furbo, Central Texas.

Wed Aug 20, 2025 12:06 pm

If I had original injection and it works - I would definitely stick with it.

Replacing parts/whole of the wiring loom is indeed not only possible but not that comprehensive - depending a bit on what parts have been "worked", vs. animals or electrical fires etc. making a general mess of it all...

Without the right exhaust back plate or new exhaust, you may not have pre-heat to the carburettor, and quality of aftermarket parts or well used original German may itself cause enough issues to solve and so forth...

If anything I would think the biggest issue would be to pull the wiring loom through, but I seem to recall that on Mexico Beetle it is easier routed than the older version inbetween the body plates at rear seat through firewall?

Wed Aug 20, 2025 12:12 pm

Worth to get feedback in the Mexico Beetle thread here; https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

This picture shows the cable loom through the main firewall, and not threaded through the gap btw. side body panel, through the "foam insulation" and in between the inner/outer rocker/channel and side body panel etc. to my understanding

Wed Aug 20, 2025 12:18 pm

Page relevant for this topic presumably; https://www.thesamba.com/vw/forum/viewtopic.php?p=9831446&highlight=#9831446

Wed Aug 20, 2025 12:41 pm

While I agree with what redhot has posted.

If you do go forward with the swap from EFI to carb. Make sure to change the fuel pump to a lower pressure output pump.
I had a 914 some idiot swapped from EFI to carb and didn't change the fuel pump.
The end result? FIRE!
This happened before I bought the car.

Wed Aug 20, 2025 2:07 pm

I did a FI to carb swap on a 1975 US spec bug many years ago. I remember the FI wiring harness was similar to what redhot showed. Once that was out of the way the basic engine harness on that car was still there. I do not know if the Mexican cars were wired like that. I remember it being an easy swap with common 70s bug carb, manifold, muffler, etc. you would need to cut the rear apron for a regular muffler or put a header with side muffler on it. You will also need a low volume electric fuel pump as rustavenger stated. Good luck Bob

Wed Aug 20, 2025 2:13 pm

I think it would be foolish to remove the FI, it may need a little work now, but once that's done it'll be ready for many more years of neglect while still running perfectly.

I'll bet it'll cost more and take longer to get a carb swap installed and working properly.