[T3] Blue Coil

[Jim Adney]

On 29 Jan 2011 at 19:15, James Lingenfelter wrote:

>      2. I THOUGHT it was ignition related since the worst running  
> I've witnessed occurred on a nasty rainy day. That was the ONE time I  
> could barely get it started.

Rainy day may be the key here. 

Under your RF fender you can feel the gas filler pipe. Just behind it 
is a molded rubber hose that runs to the high point of the gas tank, 
allowing you to the fill the tank completely. These hoses never 
lasted more than a few years, so I replaced many of them while they 
were available from VW, but they have been NLA for many years now.

That hose got dubbed the "overflow" hose, even though that's not 
actually its function. They develop tiny cracks that allow gas to run 
out under the RF fender when you top up the tank and spill gas out 
when you make hard left turns even if the tank isn't full. People 
will often stop filling the tank fully and take more moderate turns 
to try to avoid spilling gas, but the real problem occurs when water 
and dirt get IN the tank, rather than when gas gets out.

If you drive in the rain with a cracked hose, you can accumulate as 
much as a half gallon of water in your tank in a 45 minute drive. 
This is just due to the wheelspray inside the fender when you're 
driving on wet pavement. The wheelspray will also contain dirt. The 
dirt and water will cause headaches exactly like what you're having.

So, top up your tank and look to see if there's now gas running down 
the inside fender wall and onto the ground. Don't bother to look for 
cracks, as they are often too small to notice. Yours is either 
cracked or it isn't; in fact, you've either repaired it yourself, or 
its cracked, because none of them lasted more than a few years before 
needing replacement.

A few years ago, faced with the prospect of NLA parts and a total 
lack of alternative solutions, I came up with a kit to repair this 
hose. My solution isn't beautiful, but it's in a place no one will 
ever see, and I think it's actually rather elegant, since it repairs 
both early and late cars (VW supplied 2 different parts) and it 
should last much longer than the OE part.

The kit for 70-3 cars costs $30 (or $31 if you pay by PayPal) 
including postage. That includes the overflow hose parts, a second 
kit to repair the tank vent system, and all instructions. You need to 
repair the vent system at the same time because the steel lines used 
there have all rusted shut inside by now, so the cracks in your 
overflow hose have been your vent for the past decade or so.  

If you have a '71, check the vent line that runs across the top edge 
at the rear of the trunk. If that's steel, I'll need to send you some 
extra tubing to replace that also.

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