[T3] New Distributor Same Results, 034

[Jim Adney]

On 11 Jun 2014 at 7:16, Craigs List wrote:

> Along those lines, I am on my 3rd distributor combination. none of the
> distributor changes have made a difference. I have had a 009 on there, a
> 205L FI distributor and now a 034 SVDA to try and get some relief. All of
> them have acted the same.

The only thing that I can think of that might cause this problem 
would be that you're hooking the vacuum advance up to a vacuum port, 
like manifold vacuum, that's causing you to be getting vacuum retard 
instead. Try leaving the vacuum can disconnected. Time it that way 
and try driving it that way.

Most people don't realize that the vacuum advance, on dists that also 
have mech adv, is only an economy feature. It does almost nothing, 
and what it DOES do is almost totally imperceptable while driving.

If you hook one of those dists up to manifold vacuum, you'll get lots 
of advance at idle, which you don't want, but when you open the 
throttle, most of that advance will go away, providing a sudden 
retard of the spark. It's likely that your carbs don't have an 
appropriate vacuum advance port, so you should just forget about vac 
adv and use a dist that gives you lots of mech adv. That's why the 
009 and the 205L tend to work so well with aftermarket carbs.

All the mech adv dists have a common problem of seizing up the mech 
adv mechanism due to lack of lubrication. (A drop a year keeps Jim 
Adney away.) I rebuild a LOT of distributors for this cause alone. 
You should make SURE that your mech advs are working.

You can check the mech adv with a timing light or by twisting the top 
end of the shaft with respect to the bottom end. They should move 
smoothly with some spring tension and snap back when released. If 
this isn't working, however, it won't cause the symptoms you 
describe; it will just be gutless at any rpm much over idle.

Finally, there's almost nothing special that needs to happen in the 
dist as you come off idle. Except for the '72 FI dist, they all just 
advance slowly as the rpms go up, so I guess I'm saying that there 
might be something wrong in the carbs.

Your car doubtless came with FI. All US Type 3s did from '68 to '73. 
Your rebuilt engine is a question mark. What cam is in there? It 
could be anything. I know almost nothing about carbs, so I'll let 
others comment on that topic.

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