Fuel injection or carbs

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Rob 400e
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Joined: 5th August 2017 - 2:21pm
Location: Burnley

Fuel injection or carbs

Post by Rob 400e » 2nd October 2018 - 8:11pm

I've owned my fuel injected 411 for just over 12 months, it's been problematic!! My question is would most owners stick with the fuel injection or convert to carbs? I'm guessing keeping it factory is the best option but it seems parts and expertise are pretty thin on the ground regarding problem solving on the injection system. What are other owners thoughts?

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richtbiscuits
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Re: Fuel injection or carbs

Post by richtbiscuits » 2nd October 2018 - 9:01pm

I had numerous problems with my 412 LE when I first got it back on the road what with rough running and poor idle, blowing smoke and running rich. It took considerable time and patience with a methodical approach, not to mention a good deal of help and advice from members of this forum, to iron out all the problems. I found John Muir's 'How to keep your Volkswagen alive' invaluable too as it has a good deal of information on diagnostics and set-up of the fuel injection system. These days I have a nice even idle with power right through the range (although it is a bit thirsty on the urban commute!) and it's a pleasure to drive. I would say persevere with the fuel injection as it is, as you say, factory original. I'm sure all on here will help with any queries whichever way you decide to go. Good luck.
'72 412 LE Variant
'73 412 LE Variant
'83 1200 Beetle

Rob 400e
Posts: 41
Joined: 5th August 2017 - 2:21pm
Location: Burnley

Re: Fuel injection or carbs

Post by Rob 400e » 2nd October 2018 - 9:41pm

Thank you for the reply. I have almost convinced myself to stick with the fuel injection.

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broady_6
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Re: Fuel injection or carbs

Post by broady_6 » 2nd October 2018 - 10:26pm

Agree!
The sultan of swing

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937carrera
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Re: Fuel injection or carbs

Post by 937carrera » 2nd October 2018 - 11:17pm

Another vote to stick with the FI

.............. and something to help :)

http://pcbunn.cacr.caltech.edu/jjb/Pors ... tronic.pdf
David
1974 412LS Variant
1973 412LE 4 door Fastback / Saloon

Rob 400e
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Joined: 5th August 2017 - 2:21pm
Location: Burnley

Re: Fuel injection or carbs

Post by Rob 400e » 3rd October 2018 - 10:57am

Pretty comprehensive, thank you for that.

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Editor
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Re: Fuel injection or carbs

Post by Editor » 15th October 2018 - 1:32am

From my experiences with both, the carbs (twin 32PDSIT-2 and -3) work well at higher RPM, while the FI gives better low down performance. Once running well, FI will stay working well for longer, but as you say, there is a dearth of expertise for the FI. It's a simple system to get your head round, but less common in the UK.
Dave.

Rob 400e
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Joined: 5th August 2017 - 2:21pm
Location: Burnley

Re: Fuel injection or carbs

Post by Rob 400e » 17th October 2018 - 2:01pm

It seems some of my running issues may be being caused by poor vacuum, air intake manifold is going to be re sealed.... See where that goes fingers crossed.

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richtbiscuits
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Re: Fuel injection or carbs

Post by richtbiscuits » 24th October 2018 - 7:51pm

Auxiliary air regulator can be a problem too. Mine was stuck giving poor idle and rough running on warm up. If you think air supply may be a problem you could check this part. If you hold it lightly and flick the body you should hear a nice ringing 'ting' sort of sound. If it is stuck it'll be a dull 'tinck'. Fill it with carb cleaner and let it soak to unstick. Look for a good connection on the wire on the bottom too - can be a weak point. Getting AAR working properly made a big difference to my engine.
'72 412 LE Variant
'73 412 LE Variant
'83 1200 Beetle

Rob 400e
Posts: 41
Joined: 5th August 2017 - 2:21pm
Location: Burnley

Re: Fuel injection or carbs

Post by Rob 400e » 26th October 2018 - 8:09pm

Cheers for that info, will finish off sealing the air intake manifold and if needs be move onto the air regulator. Just keep working through the system.

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