[T3] My final question on IAD's

Jim Adney jadney at vwtype3.org
Tue Jul 18 09:47:34 PDT 2023

On 17 Jul 2023 at 14:32, William Jahn wrote:

> I was curious why there are two ports tee'd together on 72 and 73 fuel
> injected Auto trans models which seem to be California built cars. The is a
> CA built and Federal . I looked at mine and both ports are after the
> throttle  plate.
>  Do I need two for the trans to shift? Or will one do? I cannot find any
> info on this.

I don't know. Mine is the same and it's always bothered me, too. I THOUGHT 
one of the ports was in front of the throttle plate, at least at idle, but I haven't 
spent any time studying it. I've never seen any info on this.

I've always wondered if there was an orifice somewhere in the conductance 
between those two ports, but I've never taken anything apart.

On mine, one of the hoses wraps over the top of the #2 air runner, and time 
has crushed the hose flat there. I've wondered if this means that that hose is 
no longer working. Everything still works, except that the 2nd to 3rd shifts 
tend to slip unless I'm accelerating hard. No problem with 1st to 2nd or on 
any downshifts.

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

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