Not the microswitch, Dave. The microswitch is the black switch depressed by the throttle linkage when the throttle is closed. I know there are some pix of it on the board somewhere.

I was referring to the wiring diagram (the SL33 diagram found through the MFI references thread)

For a 1969 E/S in checking the connections. It shows the RPM Transducer as Item 69 with its pin 3 connected to the "Time Limit Switch" as Item 70 on the diagram. The microswitch is item 73 on that diagram.

For a '71 the diagram shows the RPM Transducer as Item 11 with pin 3 connected to a collection of grounds. Hopefully, the forum will let me upload the '71 diagram (have "issues" with screen refreshes).

Diagram: http://forums.pelicanparts.com/uploa...1202239618.jpg
Legend: http://forums.pelicanparts.com/uploa...1202239681.jpg



Jim

I'll admit to a brain freeze!

You are talking about the switch which keeps the enrichment solenoid closed longer than the 2 second time limit relay to assist with starting very cold engines. It's described briefly under Cold Start Solenoid above:

Here is a picture of the thermo-time switch switch from this thread: cold start enrich '71E

http://forums.pelicanparts.com/uploa...1202245214.jpg

Its function is shown in this diagram from the same thread (originally from the CMA manual).
http://forums.pelicanparts.com/uploa...1202245980.jpg
© Dr. Ing. h.c. F. Porsche A.G. Posted here for educational purposes only.

Please check out MFI simplification thread (1st draft) for a cleaned up version of this thread. Add your suggestions and I'll re-edit the thread with all the new information.