Cliff's Quadrajet Parts and Rebuild Kits

General Category => Quadrajet Carb Talk and Tips => Topic started by: Marx3 on February 13, 2016, 02:43:35 AM

Title: Egr vacum source
Post by: Marx3 on February 13, 2016, 02:43:35 AM

Regarding the vacum source in the baseplate, sitting in the front passenger side corner:
I remember talk about this source being strictly for the EGR valve.
What is that all about? I thought it was a regular ported source?

Title: Re: Egr vacum source
Post by: Cliff Ruggles on February 13, 2016, 05:48:36 AM

Most will have a either a "bleed off" slot or higher source location if it's designed for EGR.  A quick test with a vacuum gauge will determine this....Cliff

Title: Re: Egr vacum source
Post by: Marx3 on February 13, 2016, 11:07:46 PM

So the vacum signal can be a bit special and therefore unsuited for anything else than EGR, for instance the vacum advance?

Title: Re: Egr vacum source
Post by: Cliff Ruggles on February 14, 2016, 04:18:57 AM

Correct, vacuum for EGR will show a lower reading than the source intended to operate the distributor vacuum advance.

With the baseplates that use a "bleed off" slot, you can block the slot and it will function fine for the distributor.  For the high source location baseplates they will not work effectively for distributor vacuum.....Cliff

Title: Re: Egr vacum source
Post by: Marx3 on February 14, 2016, 05:30:35 AM

Allright, thanks for clear that up.