[T3] On my 73 square , what should I look at on the breather with a PCV?

Jim Adney jadney at vwtype3.org
Tue Sep 10 15:06:03 PDT 2019

On 10 Sep 2019 at 11:29, William Jahn wrote:

> I read on rennlist about the slop where the trigger points mount that
> it should be set to the center point since it will alter the point when
> the injectors fire .

That's a red herring, because Bosch advanced the injector timing by about 
30 degrees in '72. That huge change made only a tiny difference, and then 
only when the engine was cold.

> Pertronix told me these units can fail by not working or fail where it
> can cause a miss yet that does not explain why it does not miss with
> the air temp unplugged. 

Yes, we know the Pertronix is not the problem.

>  The only thing that makes sense in my mind is either there is a voltage
> drop to the ECU from the power relay.

What makes NO sense is the fact that you found and fixed a huge problem 
IN the relay and didn't see any change in operation. Fixing that should have 
made a huge improvement. Sure, check for a problem in the wires, but those 
are probably fine, unless they've been messed with a lot.

> or high resistance in the air temp sensor wires to the ECU or perhaps
> the head temp sensor to ECU 

It can't be those wires, because any "high" resistance in those wires or 
connections would still be small compared to the resistance of the sensors 

> or the air temp sensor itself is erratic when connected. 

That's possible. Have you tried a different sensor?

You might also GENTLY pull back the boot on the sensor connector and 
check to make sure the wires in there are okay. It might be that just moving 
the cable is what's making the difference..

> I've checked the fuel pressure several times and it's always 30 PSI .

When there are problems, I prefer to test it while driving, because a 
restriction in the line, a clogged filter, bad pump (or bad power to the pump) 
or kinked hose, can still source enough fuel to hold 30 psi at idle, while 
failing at speed, where the demand for fuel is greater. Nevertheless, you 
report this problem only at idle, with no problem while driving, so I'm thinking 
this is not your problem.  

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

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