New 71 Fastback less motor. F.I. or dual carbs?

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Hi all, I recently save a 71 automatic fastback from being junked. The car is very solid and complete minus the motor. I'm currently putting together a long block with correct automatic case but not sure if I should go with dual carbs or try and piece together the F.I. The car still has the computer and F.I. harness installed.
From what I'm seeing it looks like there are changes for almost every year of the D-jet F.I.
I would prefer to keep it Fuel injected but have zero experience with D-jetronic, however I am with L-jet.
Thanks for reading. Any advice or thoughts are appreciated.
Justin
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77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[KTPhil]

Opinions vary. People can make both work. A good original dual carb setup with the proper air cleaner will cost as much or more than the FI equipment. Once running, the FI is pretty bulletproof, save for the need to replace hoses and the fragile 45 year old wiring harness. You can get all the parts used (which will almost always work as good as new) in the Samba classifieds.

Is the harness "crispy?" A replacement is a few bills all by itself, but will then last the life of the car.

Keep in mind the automatic means a few different pieces that can be harder to find, carb or FI. The throttle mechanism needs the proper kickdown switch, and the FI AAR is different on an automatic. The pipes and hoses for a dual carb automatic (for vacuum shift control) can also be a little larder to find.

I like the original FI and the proper cool intake air. But many have put OEM dual carbs on these cars.

I'd price the FI and carb parts, evaluate the harness, and then decide.

[Bobnotch]

[Donnie strickland]

[[email protected]]

So I went out and took a look at few things. I don't see any vacuum hoses coming from the transmission although I may have over looked. ( It's covered in snow at the moment. ) and the harness looks to have been repaired in a few spots. I do see hoses coming from an EVAP canister mounted above the transmission and 2 fuel lines on each side.
When I purchased the car I also purchased a complete or mostly complete seized F.I. motor that was supposed to be for the car but the project was abandoned. That came with 2 additional harnesses and computers. Both are for 1968 I think. As for the year of the motor and its F.I. I'm not sure but it's from a Manual Transmission car.
It has a manual type AAR that mounts in the case where the fuel pump would be if I'm referring to the correct part.
Is the plenum and throttle body the same?
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[KTPhil]

The vacuum hose to the tranny connects at the modulator at the bottom toward the rear, IIRC.

Harnesses are specific to the "generation" of FI: 68/69, 70/71, and 72/73. They don't interchange, but the individual connectors can be harvested from one and used on another.

Plenum/throttle body (aka, the intake air distributor, or IAD), changed over the years, mostly along the same break points as the wiring.

If you do go FI, I'd either invest in a new harness, or put a lot of work into your old ones, replacing or crimping the metal connectors inside all the plastic housings at the engine connectors. It will make it much more reliable.

[[email protected]]

Thank you for the responses and information. I'm going to keep it fuel injected at this point. I prefer keeping it original especially since the car is original and very complete. I want it to be smooth and reliable. I just need to sort out the correct parts for 71 and pick up a Bentley service manual. That might help sort some of it out.
I'm still slightly confused on the IAD intake air distributor and AAR auxiliary air regulator. Are they both automatic specific? And is the computer and harness also automatic specific?
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[KTPhil]

Computer and harness are the same for manual and automatic.

AAR is mechanical for the stick shift, and electric for the automatic. Explanations vary as to why they were made different, but they can in fact be interchanged with a bit of work; this may help you because the mechanical units are a little more obtainable than the automatic units. Hot startup may mean a low idle on the automatic for a few miles.

IAD is different because of the throttle arm, which differs for manual and automatics. The automatic also has an additional hose connection.

Here is a table of part numbers:

[[email protected]]

Thank you. It's starting to make more sense to me now. The motor that I got with the car and its F.I. are 1968. case is U 0088501 and control unit 311 906 021A so it must be early 1968.
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[Donnie strickland]

The 70-71 system is probably the easiest to work with, in that it has fewer components than the the earlier system and no emissions issues like the later system.
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71 Elm Green FI A/T Squareback

[grethi]

[Bobnotch]

[KTPhil]

'68/'69 is pretty bulletproof, but lacks up the altitude compensation and the "accel pump" injections from the later throttle valve switch, so it can have a minor flat spot from leanness under part load conditions.

'70/'71 seems to run best, but the MPS is a little more particular to adjust.

'72/'73 added smog complications, especially in California automatic cars, but runs well if set 100% right.

Any can be made to work, but avoid mix/match of components. Only certain combos, with certain modifications, can be made to work if you mix-- best not to go there. No need if you can wait for them to come up in the classifieds.

[[email protected]]

I've been looking in the classifieds and found a complete setup from a 70. I messaged the seller and waiting for a response. I'm hoping to have it together running by spring if I can.
Is it possible to use all the 68/69 parts I already have but use the 71 computer, harness and MPS that is still in the car? then all I would need is the automatic IAD with the kick down mechanism.
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[[email protected]]

Never mind the mismatching. I read back seeing that they are not interchangeable.
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[Donnie strickland]

When you say "complete setup", how complete is it? Does it include the IAD? And the correct air cleaner?

The A/B (68-69) system uses a pressure switch, which was deleted on the later systems, so those harnesses don't have a connection for it. The cold start system went through several variations as well, although you don't have to use that (mine is not connected). The throttle valve switch has two pins on the A/B cars, four on C/D cars, and five on E cars. The distributors from 68-69 can be used on 70-71 models, but 72-73 distributors should be used only with those systems. You'll probably want to send your distributor to Jim Adney for rebuild for smoothest running.

The 73 cars had EGR and a PCV valve, with forced air ventilation through the valve covers, which means more hoses. You don't have to worry about the evap canister; I'd go ahead and remove it while the engine is out, along with the charcoal canister under the left front fender, if it's still there. Also, the gas tank vent system should be replaced so you don't get water and dirt in the fuel system. Jim sells a kit for that, but you can do that once the car is running.

This is why it's easiest to use the whole system together. But some parts are common. Injectors are all the same, for example.
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71 Elm Green FI A/T Squareback

[Multi69s]

In all honesty, I'm a carb man. However when I first got my Square, it was stock and FI. However, it had sat for many years, and needed a little love. Ray G basically held my hand and guided me through the whole tuning/trouble shooting process on STF. Hands down FI is better than dual Solexes on a stock engine. However, the engine needs to be in good condition. The same for the charging system and the distributer. No short cuts are allowed. I wouldn't worry about a kick down for the auto at this point. Get the engine running good and I can show you how to make one that mimics the stock one fairly well.
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69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[[email protected]]

I was torn with which way to go with this. I have a 67 Squareback bone stock with dual solex carbs and love it. It runs great and has never let me down. I mean sure...I had to rebuild them when I bought the car and get it running good but I drive it daily in the summer. As far as F.I. I have 3 late bays all L-jet. Love the smooth and reliable F.I. I've worked with it for many years and love how simple and reliable it is. I'm just totally new to D-jet and trying to understand it and get everything together while I'm building the motor over the winter.
I appreciate all the feed back. I'm looking forward to the challenge but to be honest I have been wondering what it would take to run L-jet on it
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong

[Bobnotch]

[[email protected]]

I'm to much of a stock guy for that. I'm just much more experience with L-jet.
Its not like I need the car running tomorrow. I have plenty of VW's to run, but I would like to be able to run it in and out of the garage while I'm working on it.
_________________
77 Champagne Edition I
78 Champagne Westy II
67 Squareback
69 Single cab
88 Wolfsburg Vanagon
89 Vanagon Syncro
2001 Golf TDI 354,000 and running strong