Help identify this mistery contact switch.

[ulrichd]

Found loose in my 70T engine compartment. Push button type electrical switch, wires on the other end seem to also be disconnected.

Any clue? Thanks in advance.

Ulrich

[boxster03]

maybe an MFI Microswitch

[JHunter]

Where was it located? Is it possible a previous owner set-up a remote starter switch?

[304065]

Ulrich, that is for overrun fuel cutoff on a '70T. The "Speed switch" actually was used for carbureted cars for a similar function. Do you see the sector-shaped piece on the throttle shaft in the background? That contacts the microswitch.

[Gearbox]

The switch prevents that burbbly backfiring you get on deacceleration and while changing gears. On MFI cars it activates a fuel cut off soleniod and is controlled by an electronic box that is located on the left relay/fuse panel. Quite clever, the box senses if the RPMs are above 2500 and once the microswitch is depressed when you go "off" throttle, it activates the fuel cut off soleniod preventing fuel over run and thus the backfiring. Not sure how it exactly works on carburated cars but I just fixed mine and it's like night and day, no more embarassing popping when you slow down for a turn or when shifting. Hope this helps, Allan

[Neil '67 911S]

Actually, that button activates the "Way Back" machine.

"Sherman, today we are going to visit Gmund, Austria, where the first Porsches were built."

- Professor Peabody
'67 911S

[Bummler]

OK Mr. Peabody...

[JHunter]

Too funny!

[ljowdy]

Mystery !!!!

[ulrichd]

The switch prevents that burbbly backfiring you get on deacceleration and while changing gears. On MFI cars it activates a fuel cut off soleniod and is controlled by an electronic box that is located on the left relay/fuse panel. Quite clever, the box senses if the RPMs are above 2500 and once the microswitch is depressed when you go "off" throttle, it activates the fuel cut off soleniod preventing fuel over run and thus the backfiring. Not sure how it exactly works on carburated cars but I just fixed mine and it's like night and day, no more embarassing popping when you slow down for a turn or when shifting. Hope this helps, Allan

Thank you very much for taking the time to answer and the pic.

Ulrich