Thread: Vacum advance or Carburator problem?

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Running 'timed' - or ported, same thing - vacuum to the distributor usually results in a hot running engine at idle and low speeds in traffic on hot days and most times even on cool days.

GM developed the ported vacuum bit to improve the Nox smog situation by making the engine run hot.

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Ported vacuum to the trans results in no to low vacuum at idle and just off idle so the trans won't shift properly.

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Full time manifold vacuum can be sourced for the vacuum can on the drivers (left) side bib at the front of the carb.
The right side bib is ported vacuum - passenger side in the US.

Trans vacuum can be pulled from the large fitting at the front or rear of the larger center bibs on the carb.

Depends on whether you're running a PCV system or not.
If you are you want a dedicated large bib to connect the PCV directly to.
Main thing is to keep the PCV sysem separate from the trans modulater.
It doesn't hurt anything if you don't, but there's a chance you'll load the modulater line with oil which also won't hurt, but you're liable to get a huge puff of smoke when you roll the throttle on hard.

Now thats a mouthful!! Right on!! Thank you very much for the VERY much needed lesson.