Cold start throttle on 911s, when did they change this system?
 

I'm wondering why the throttle to begin with (something inherent in the design of the engine?), and what year was this system changed to other?

Thanks

Supposedly the hand throttle went away for the '76 model year (I believe), but my '76 still has one.

Not sure of the exact function, but it sure helped the CIS idle a little better when cold...

Mike

Wow 6-7 years later. Wonder if this was used with 356s too, and if the cold throttle was due to air cooled design necessity?

When I dropped my SC motor into my '74, I kept the cold start throttle, so you can use them with later motors. It definitely wasn't there for the SC, and probably not for the '76-'77 Carreras, since they had, more or less SC motors with some 2.7 bits in there. So I'll say '75.

I love 'em. It really helps the CIS come up to snuff in about a block's drive on mine. If at all, they're a great "poor man's cruise control" even though I hate cruise control. :)

The hand throttle was used on MFI cars and early CIS.

They were used to allow airflow for increased cold engine idle. Later CIS engines had an Auxillary Air Valve that did this job "automatically".

I have bypassed the anoying AAV and am looking into retro-fitting a hand throttle. The one on my old 73T sure was nice!