Large RPM and Vacuum drop when shifting from park to gear

Well, unless you can't suck very hard ,lol.
Don't laugh, using lung-power alone, I doubt you can get anything started.
There is a technique;
You put the line between your teeth and suck, then capture the vacuum in the line by biting down,repeating as often as it takes that the rpm no longer rises. Then, still biting down, if you have a lite, read your timing. Then relax your bite and read again. If your diaphragm is not leaking, you will get a difference. If your diaphragm is perforated, you will not get any vacuum built up, and so, no timing difference..
I Tee a vacuum gauge into the line and can read the progress. It takes a good technique and a lotta lung power to hit 15 or so.


LOL...I have a machine to do that for me!!