TheSamba.com :: View topic - Super Beetle 1979 - Re-Converting FI/Carbs or Dual Cars

Mon Jun 09, 2025 9:11 am

Dear all,

The car is a late model 1979 super beetle, original with fuel injection while I believe without catalytic converter.

It was at some stage converted to standard 1600 with carburetor (full engine swap, Solex 34-PICT3, non-vacuum advance distributor), hence missing all specific parts less the exhaust system based on my understanding and basic inspection.

Due to the missing pre-heat pipes to the inlet manifold, it has then the known stumble and hesitation due to either/both this combination.

Living in fairly cold climate for a cabriolet, the seaons temperature should be expeted as from ca. 10degC/50degF (driving in morning/late evening) to peak closer to 30degC/86degF. Mostly it would be in the lower mid-range of this span.

As I see it I have some basic options, with hopefully your help to rank in terms of reliability, cost, originality etc.

1. Add heat to manifold - I have not seen any good way of this integrated with the fuel injection exhaust

2. Add non-fuel injection exhaust, adapted to the single apron outlet (Vintage Exhaust?) and then heat to manifold. Should other issues be expected?

3. Convert back to original fuel injection - possibly some issues with engine block, heads etc. that cannot be fully known/resolved with engine in car? Assume some minor work for e.g. engine tins, head temperature sensor, etc. The fuel tank and otherwise is already there and original to my knowledge, but may require new pump, filter hoses etc. that is more of a maintenance. Otherwise significant possible issues related to parts availabilty/obsolecesene.

4. Convert to "Mexi-injection"; not fully sure or issues here or if one should expect parts availabilty/obsolecesene.

5. Convert to new 'electric carb' - while to my understanding one should still expect similar issues as fuel is injected in the center portion with a horizontal intake following on.

6. Convert to injection at head type modern fuel injection; possible while has somewhat a bit ot "tinkering" as I have looked through kits and otherwise support, parts etc. It is no to my finding something along a OEM level approach kit where one would not need to have laptop, some in depth electronics knowledge etc. (turn-key as in original ,working ignition)

7. Convert to dual-carburettors, and hence vertical runner and some heat from short inlet manifold. Though diverging from original parts bin approach.

And maybe something more I have forgotten... Being e.g. tuning in the current combination, add only SV/DV distributor and ensuring the ignition is not contributing to best ability (electric configurable distributor, e.g. 1-2-3 ignition?)

If I rank the priorities being reliable, originality and then cost, with good basic mechanical/electric abilities; what would the crowd recommend?

Mon Jun 09, 2025 9:40 am

Most dual carbs don't have chokes so that's a problem.

Replacing the exhaust not only mean the muffler, you also need new heater boxes. Then you can replace the intake with on that has heat riser.

Mon Jun 09, 2025 10:43 am

Most FI to carb conversions are done by lazy people, have a look on the top of #4 head for the temp sensor, it may still be there, or at least the hole for it. The fuel pump is often left in place up front too.

Mon Jun 09, 2025 10:59 am

busdaddy wrote: Most FI to carb conversions are done by lazy people, have a look on the top of #4 head for the temp sensor, it may still be there, or at least the hole for it. The fuel pump is often left in place up front too.
Most anything done by previous VW owners is done cheaply.

Removing the FI and replacing it with a aftermarket 34PICT-3 and 009 is most common. There is no economical way to use the heat risers without replacing the muffler and heater boxes.

As to the fuel pump, you need an electric pump since the case does not have the opening for a mechanical So either use the existing with a regulator or replace it with an electric that puts out 3.5 PSI.

Also fixing the old FI can consume a lot of hours of labor and time finding working replacement parts.

So I bet 99% of FI to carb conversions are done CHEAP.

Mon Jun 09, 2025 11:44 am

I agree, 9 X out of 10 cheap and lazy are the main factors driving a job like that.

On top of what you have already mentioned there's the rear breastplate tin, cylinder tins and apron modification to swap to the carb style exhaust..

FI isn't a big challenge, most parts are easy to find, the rest are out there but require a little searching. Depending on how intact the FI exhaust is and how much of the rest of the system still remains it's not out of thhe question to convert back.

Mon Jun 09, 2025 1:19 pm

Thanks for the tips so far.

The FI exhaust and heater boxes are in place. The car was a non-catalyst based on the sticker.

The engine tin etc. (ahove seal) have been swapped out it seems.

Replacing the rear apron is not on option list; it would have to be an exhaust and heater boxes (J-tubes is possible, but not desired) that fits the existing, righthand cut-out of the bulged apron type. Mexican cars have the single outlet on the left as I can see and maybe also slightly more towards centre.

The fuel tank is indeed FI (two hoses coming out, 1 plugged now due to being dead ended in carburettor).

Top of my preference would be original FI given that it is possible without major sourcing efforts of key parts plus possible with refurbishable/new wear parts (injectors and rubber hoses/items only?). Not sure if anyone can service the AFM or ECU, but they should be replaceable if one collects a minor stock.

Mon Jun 09, 2025 1:21 pm

No need to replace the apron, just add a cutout to the existing apron. There's a flat section along the bottom and that's what everyone uses.

Mon Jun 09, 2025 2:14 pm

@ red-hot ...

Glenn answered your query indirectly, as did you in your 1st description.

PICT3 carb paired with non vacuum distributor is known for hesitation. Well documented.
New Chinese ones are hit or miss but a restored German is best - buy once, cry once.

"034" distributor (SVDA) should be a nice pairing, provided carburetor is tuned reasonably well.
Accelerator pump should also give instant, full squirt when linkage is pulled.

Best luck ... stay safe

jinx

Mon Jun 09, 2025 2:56 pm

If you do decide to go back to the FI here's a parts list: https://www.thesamba.com/vw/forum/viewtopic.php?t=670338&highlight=injection+conversion , it says bus but the system is the same in a bug except for the manifold, and some part numbers of course.
The Samba classifieds usually has parts or complete systems for sale.

Tue Jun 10, 2025 10:59 am

busdaddy wrote: If you do decide to go back to the FI here's a parts list: https://www.thesamba.com/vw/forum/viewtopic.php?t=670338&highlight=injection+conversion , it says bus but the system is the same in a bug except for the manifold, and some part numbers of course.
The Samba classifieds usually has parts or complete systems for sale.

THanks! This post is now both bookmarked and printed for reference!

Tue Jun 10, 2025 11:18 am

jinx758 wrote: @ red-hot ...

Glenn answered your query indirectly, as did you in your 1st description.

PICT3 carb paired with non vacuum distributor is known for hesitation. Well documented.
New Chinese ones are hit or miss but a restored German is best - buy once, cry once.

"034" distributor (SVDA) should be a nice pairing, provided carburetor is tuned reasonably well.
Accelerator pump should also give instant, full squirt when linkage is pulled.

Best luck ... stay safe

jinx

A simple distributor in the between time cannot hurt. I have seen some forum recommended sources like Aircooled-net (lack of cores?), Glenn, Heimlich, Sparxwerx etc. - and without rememebering the part name etc. my mental notes are *034 & *205 (just need to refresh / read up again...). These should in principle be plentiful in Europe given a very standard setup (less heat to manifold).

https://www.thesamba.com/vw/archives/manuals/Bosch_Tune_Up_Parts/Bosch_Tune_Up_Parts.pdf

Tue Jun 10, 2025 11:24 am

Glenn wrote: No need to replace the apron, just add a cutout to the existing apron. There's a flat section along the bottom and that's what everyone uses.

An otherwise original 1979 cabriolet in all black will keep its original feathers where can be :)

But yes, simple if one wanted or did a very comprehensive modification with less emphasis on originality. This car to my knowledge has no panel replacements although some minor body work and paint along its lifespan. And a very irritating parking fender bump on the lower left one while should be manageble by micro-corretion/non-repaint type dent correction.

Tue Jun 10, 2025 11:45 am

redhot wrote: An otherwise original 1979 cabriolet in all black will keep its original feathers where can be :)
Then you must replace the original fuel injection.

Tue Jun 10, 2025 12:35 pm

Lotta good advice above. I actually like the Mexibeetle EFI, and have been imagining ways to need to acquire the set up. Quite a bit more modern, and it's factory.

There's a lot to be said about using what was meant to be on the car and keeping it running well, however, as the years pass, that will become more and more difficult. Also, keep in mind most, if not all, replacement parts will be used

H2OSB

Tue Jun 10, 2025 4:02 pm

Back in 2018 I bought 2 Craptek SVDA distributors from Scamazon - ( Kuhltek ). One ran till last Feb when the condenser finally shorted. The 2nd one I kept in a Ziploc bag stored indoors all those years. Not bad for $42each.
Now they're about $55.

I can't recommend them as it's hit or miss.
I got lucky.

All I did was spray carburetor or contact cleaner on plate - can't remember which - dirty crud came out (new, outta box) followed by WD40, 2drops of oil on wick, & set the points.

Good luck ... stay safe

jinx

Tue Jun 10, 2025 6:08 pm

If you are considering a return to FI (best idea if the car is very OG aside from the carb) then the correct distributor for the year and model is the best choice, it'll work fairly well with carb(s) as well in case you change your mind or don't get around to the swap right away.
Bill can hook you up with the correct unit: https://www.sparxwerks.com/

Mon Aug 04, 2025 3:06 pm

For information - since I did not find this originally, and maybe others also have missed it;

Vintage Speed provides a US FI system (also Mexico with tailpipe on the left) that also enables heat risers for the inlet manifold. Further, one may then to my understanding use standard heater boxes / J-tubes. So adds to the possibilities of both "performance" or hopefully quality aftermarket options, or a conversion that actually works as intended (it states that heat-risers have a positive/negative pressure design...)

https://store.vintagespeed.com.tw/Pre-1979-Injection-Beetle-High-Performance-Muffler-c33978116