This totally confuses me (sponsor peek at this)

[JFP in PA]

In order for the car to start, the DME has to see a signal from the crank position sensor telling the DME that the engine is rotating, it then turns on power to both the ignition and fuel pump. If the DME does not see that mV signal from the CPS, the fuel pump will not get power, and the car will not run.

[Luckyman01]

However, I replaced about 5K miles ago and the tach needle appears to move (ever slightly) so I dismissed that.

I am however unclear on how much movement I should see out of the tach.

Is there any support for ignition switch theory?

[blue62]

Originally Posted by Luckyman01

However, I replaced about 5K miles ago and the tach needle appears to move (ever slightly) so I dismissed that.

I am however unclear on how much movement I should see out of the tach.

Is there any support for ignition switch theory?

You could test the CPS with a volt meter at the nearest connection by back probing or unplugging the connector and probing the CPS side.
When you crank the engine you will get a signal if the CPS is good.
That way your no longer guessing if the CPS is good or not.
Or I believe you can check the CPS signal with an OBDII reader that has a Porsche program.
Like a Durametric or Foxwell