[T3] T-3 Distributor

[Jim Adney]

On 10 Mar 2014 at 22:31, rheorojo at F wrote:

> Got the distributor ready to go. I'll include the capacitor also as it
> is a little different, but is a Bosch. The arc point is visible on the
> barrel of the unit.

Circle that arc point with a marker if you can, so I know exactly 
where to look.

> I've been slowly checking the fuel economy issues, to rule out
> components. I replaced the voltage regulator with the new electronic
> version, and installed a small volt meter direct from the battery. I
> get a solid 14.1 at mid rpm's. I tried disconnecting the throttle
> position sensor and didn't feel a lot of change. 

Okay, this is good. The charging system is not a problem and the TPS 
actually never has much effect on gas mileage.

> The fuel situation started a few years back after I was advised my old
> injectors were faulty. Since then it's been around 20 mpg. I got taken
> on that one. I have another set but as of now have not attacked them.
> They have been sitting dry for several years and I'm uncertain on the
> proper procedure to get them in. I've read the seals can dry out and
> then they leak. I don't want to go there so I'm a deer in the
> headlights. 

20 mi/gal really isn't particularly low. I often get this kind of 
mileage in city driving, especially in cooler weather when warmup is 
longer. How about your thermostat system? Is it all there and 
working? If it's been removed, that will dramatically prolong warmup 
and reduce your gas mileage.

> I don't see any obvious signs of wrong injectors such as fouled/lean
> running plugs, or excess smoke/vapor when it's running. The exhaust
> doesn't smell like unburned gas so I'm not convinced the injectors are
> wrong. Just a suspicion. Besides I really enjoy driving the car even
> though it's not right, I just keep reading and thinking and tinkering.
> Last time I checked the fuel pressure was at 28 psi. I haven't changed
> the fuel filter in a while so that is next.  This forum is a must for
> me with my coffee every morning. 

If your injectors have the yellow plastic bodies, they're probably 
right. You want them to be Bosch, not aftermarket, but that can be 
hard to tell when they're installed. Look closely at the shape of the 
plastic around the electrical connector. The Bosch ones will have 
smooth and rounded corners, while the aftermarket ones I've seen will 
have squared off corners.  

I've never seen fuel pressure change on its own, so if you've checked 
it once, you should be set. (Keith had something odd happen to his at 
one point, so it's POSSIBLE for something to go wrong, but very 
unlikely.)

My FLAPS has an injector cleaner and I've used it. The head guy there 
tells me that certain styles of injectors tend to get clogged and 
others just don't. Our style does not tend to get clogged. My 
experience with his cleaner is that cleaning our injectors does not 
change anything.

One thing that WILL affect the injectors is water in the fuel. This 
will cause rust that can affect fuel delivery. The cleaning machines 
out there won't improve this. (BTW, no one takes our injectors apart 
to replace the internal O-rings. It's too much work. They just 
replace the hoses and the little inlet filters. If they leak to the 
outside world, other than hose leaks, you really have to replace 
them.)

I store my used injectors in kerosene, in plastic peanut butter jars. 
That will keep the O-rings from drying out.

The most important thing that you might need to do would be to fix 
your overflow hose, under the RF fender. If it's cracked, so that you 
leak gas when you fill up the tank, it's cracked. Those cracks will 
let gas out, but, more importantly, let dirt and water in, especially 
when driving in the rain. The OG part is NLA, but I make up kits to 
fix this problem, and my repair is more robust than the original 
part.

At 20 mi/gal I'm thinking that you may not have a problem at all. 
Take it on a trip and see what you get. If you keep your speed down 
to 60-65 you may get as high as 28, but your mileage will go down as 
your speed goes up.

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