# Timing manifold vacuum



## rheckman (Aug 28, 2018)

I know there are numerous threads about ported and manifold vacuum,my quadrajet has no ported vac.
I believe this model quadrajet in 1970 ram air 3 came without.
I have full manifold vac advance.My question is should base timing still be set with vac plugged?
Because at idle and around 950 rpm with manifold connected it is much higher than base timing as it should be.
Thanks
RH


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## Old Man Taylor (May 9, 2011)

Yes, the vacuum advance must be disabled to set the base timing.


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## rheckman (Aug 28, 2018)

Thanks,so timing at idle With with manifold vacuum connected should show higher


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## Old Man Taylor (May 9, 2011)

Yes.


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## BearGFR (Aug 25, 2008)

Always set timing with vacuum canister disconnected. Always. Doesn't matter if you normally use a ported source or not.


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## rheckman (Aug 28, 2018)

Thanks


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