[T3] FI to Carb conversion

[Jim Adney]

On 16 Nov 2013 at 10:10, Terrie Ann Schmearer wrote:

> The time has come. My '72 T3 1600 Fastback is going to be converted
> from FI to carbs. Didn't think I'd ever do that. However, I haven't
> been able to drive it for over a year and we've put around $6000 in
> repairs in it and it's time. My (new) mechanic has been speaking to
> other classic VW mechanics who have all said to convert. I gave him
> permission to do so. He said if I could ask y'all for any information
> about converting it, that would help him get it done faster. He has to
> research how to do it. So! If any of you have experience, know what
> parts are needed, know where to get them. Any information whether it
> seems insignificant or very important will be appreciated. 

Terrie,

I've been pondering how best to respond to your message. I think I 
understand your frustration with the FI, but I'm worried that you 
expect the carbs to be a straightforward, although drastic, solution. 
I'm afraid that this is unlikely to turn out the way you hope. Carbs 
are only simple when they have someone behind them to design them 
into the car. Adding new carbs to an old engine requires someone who 
REALLY understands carbs and is willing to spend the time and effort 
to get them jetted right. It is NOT a matter of simply bolting them 
into place and driving off.

Getting the carbs jetted properly takes dedicated and knowledgable 
owners 6-12 months. The "simple" process of finding and installing a 
suitable dual carb throttle linkage is also a big deal. When I look 
at the variety of aftermarket linkages on the carb converts I see 
when we all get together, I'm amazed at how truly awful many of them 
are. Now, you could get around all this by finding and installing a 
complete set of carbs, linkages, and air cleaner from a '67 or 
earlier Type 3, where you have the VW engineering and testing staff 
behind you to make sure that this system will work, but those are 
going to be hard to find, AND you are almost certain to come up short 
on a hard to find, but important, part.

It doesn't sound to me like your new mechanic is likely to know how 
to get this working well for you once it's installed. It's one thing 
to be able to work on a car that came with carbs, because those carbs 
worked when they were new. It's an entirely different matter to try 
to install carbs and do all the jetting properly yourself. Remember, 
when these cars came with carbs from the factory, they had hundreds 
of engineers and testers behind the design. It's extremely common for 
conversions like this to be done, and then for the mechanic to drop 
the rest of the job back in the lap of the owner. The fact of the 
matter is that there's no way he could charge you enough to finish 
the job.

The reason "all" mechanics suggest converting to carbs is that they 
THINK they understand carbs and they KNOW that they don't understand 
our FI. In fact, they probably don't understand carbs much better 
than they understand our FI. It's as hard to find a mechanic who 
really understands carbs as it is to find one that understands our 
FI.

I had a customer once who taught me something interesting: There are 
things you know, and that's good. There are things you don't know, 
and that's okay. But the things that you THINK you know, but don't, 
those are the really bad things. He called those things "The Dark 
Side." Those are the things that will get you in trouble.

I don't remember if you've posted your problems and symptoms here. If 
you would do that, we might be able to help you. Let us know what 
you've done and how that turned out. What did you do that cost $6000? 
Is this just what you've spent on mechanics who couldn't find the 
problem? That's a huge amount to spend for no positive outcome.

Do I recall correctly that you are in upstate NY? If so, get Keith 
Park to help you next spring, or consider towing the car to the next 
Type 3 Invasion in upstate NY next June. If not, tell us where you 
are and what's wrong with the car. Someone here may be close enough 
to help you. If you're not interested in working on it yourself, 
perhaps your mechanic would care to join us here and discuss the   
problem. We'd really like to help, and I'd REALLY hate to see you 
dump hundreds of dollars more into a car that ends up running really 
rich, with terrible gas mileage, rapid ring wear, and won't hardly 
run except in warm weather. Those are likely outcomes with a typical 
carb conversion.

Consider towing to the next Invasion. At the past 2 Invasions I have 
resurrected a non-working FI car at each one. The first one was easy, 
took only about 15 minutes, but that car drove to the Invasion the 
day before. The more recent one took me 2 days, but it hadn't run in 
20 years, and had been worked on (messed up) by multiple people.

-- 
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Jim Adney, jadney at vwtype3.org
Madison, Wisconsin, USA
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