Distributor vacuum advance

[Frog2Spider]

Another question for you Fiat Gurus ...

At what RPM should the vacuum be sufficient to start the advance of the distributor timing?

Thanks,
Dave.

[So Cal Mark]

it's not rpm, it's load that determines the vacuum unit working

[Frog2Spider]

Well, now I'm confused!

I recently started to re-set my timing, but checked the vacuum advance first. With the engine running, sucking on a temporary vacuum line to the distributor's vacuum advance module, the engine did not speed up. Also, with the engine off, I was unable to hold vacuum on this line. Bad vacuum advance module.

I also found that I was getting no vacuum from the actual vacuum line that runs to the module, with the engine on or off idle.

Hence my question as to what RPM I should expect to feel vacuum from this line.

Thanks,
Dave.

[So Cal Mark]

the advance should be connected to ported vacuum, so the throttle has to be open. High vacuum is achieved at part throttle with very little load on the motor