Ported from venturi. Manifold from.... um.....
intake manifold.
Reading more from ifsja:
An engine with a functioning EGR valve and no plugged-up passages in the EGR system, will not idle with an EGR valve connected to manifold vacuum.
Now it is possible you confused manifold vacuum with port vacuum. Port vacuum signal is generated via Burneulli's Principle in the carb's venturi. The larger the volume of air flowing through the carb., the stronger the vac. signal. At idle there is very little air flowing through the carb and the vac. signal is very small. Basically no vacuum. At wide-open throttle (WOT) and high RPM, the port vacuum signal is strongest.
The EGR valve's diaphragm is hooked ultimately to port vacuum. At idle there is no signal and the valve is closed.
At WOT, the valve would be fully open except there is a calibrated vac. switch inline which is referenced to manifold vacuum and will dump the port vac. signal, closing the EGR valve, when the engine is under a significant load.
Okay. The bolded part above. Is this the cto switch at the rear of the intake? Or is it the delay switch on air cleaner housing?
Mine is hooked up as the above image shows. This is with the 2150.
The summit has a single port in the venturi that is spec'd for the dizzy advance. According to kansasboy, I'll tee into this using a delay valve (little round disc thingy on vacuum lines) and use it to allow egr.
My 1st question is this: Where exactly does the 2150 pull the egr vacuum from? Is it pulling from the venturi? The port looks physically low for that, but I've not had the carb off of the Jeep to actually look at it.
Secondly, would I basically hook up the egr on my new intake the same way as shown above (the way it is currently routed through the delay and CTO)?