Fuel Lines

[sneekerz at comcast.net]

Couple questions perhaps I can shed some light on, but I'm by no means an expert (or maybe I'm the stereotypical expert? make your own assumptions; I do..) anyway, 

>   Are there any durability issues with the plastic lines used on the old 
> VWs?
I have an '85 Vanagon which uses some plastic bits for fuel line connections. They have brittled in the last 19+ years. A couple of the pieces have crumpled with very little pressure. 
> My '88 Scirocco has metal lines.  I suspect they went to plastic when they
> went to Digifant.  Digi only runs like 35psi -- maybe the plastic ones
> couldn't handle the high pressures of CIS operation.
The early vanagons (pre Digifant) used a Digijet injection, which I think ran higher pressure than the later, but I can't give you a number right at the moment. I'm positive it's a higher pressure tho..
> i've never seen a problem with the plastic lines.  they fair really well in
> accidents.  i have done some abusive testing in the junk yards on them and
> they are quite resilient.  
> >   Are there any durability issues with the plastic lines used on the old
> > VWs?
As stated above, the get brittle. When replacing lines, I tried a light twist on one piece and it fell to bits quite easily. I replaced it with non-plastic. 

So, all in all, I'd venture to say the plastic is great for 15 or so years, then starts to go downhill. I'd be suspect of any in older cars, and have started replacing all the remaining pieces in the vw. This car also has nylon line in a few places. This has held up fine: still flexible and quite capable of carrying fuel under pressure. 

steve
couple '86 q's
'85 westy
kent, wa