Vacuum leak port

[Jeff777]

I have a 1973 911E 2.4 l MFI which is idling rough. This rough idle has made it pretty difficult to set the timing right as it is low and when I try to set the timing at 5 ATDC it gets worse. I would like to do a vacuum leak check and a smoke generator check. I’ve gone through my manuals and google searched but can’t find where is the best port to hook up the mityvac for vacuum pressure check and, if there is a leak, hook up a smoke generator.
Can anyone please point these out, hopefully with pics.

Thanks

[boyt911sc]

Jeff,

You will never get a vacuum reading using a hand held Mity Vac Pump (manually operated) for your 911 unless you use an electric pump. A pressurized smoke generator is sufficient to locate those hard to find air leak sources.

Tony

[rowingone]

Set your total timing at high rpm . . that way rough idle is not a factor.