EGR Valve not holding vacuum
 

Hello All,
So i'm trying to figure out what the EGR valve will affect. It is not holding a good vacuum. And, probably I need to replace it while I'm in the engine, etc. But, when does it affect the performance, idle, mid range, etc.)?
So far the engine will start and run, but the idle is rough at about 500-600rpm after sitting. I am replacing all the vacuum/air feed lines...the fuel injectors are cleaned and calibrated, etc. etc. So, I'm looking for the EGR affect mostly at this point.
Thanks in advance, Jeff

The EGR is useless and can just be disconnected or removed (and cap the vacuum source). Your info says you're in AZ, so no smog testing for you anyway (not that it does anything. S5s don't even have them). If by not holding vacuum you mean it has a leak in the diaphram, that can affect your idle. It will create a small vacuum leak under idle and low load conditions. I'd also take a look in the FSM or a Haynes manual for info on setting the idle. Adjusting the mixture w/ the variable resistor can smooth it out, and the air bypass screw on the throttle body can bump the speed up. If they can't do enough, the throttle stop is adjustable as well.

the vacuum leak OF the EGR valve is a problem. the rotary engine, due to the port overlap, has a high internal EGR at low engine speeds anyways, the EGR valve should do about nothing at idle.

so just to recap, vacuum leak is bad, egr valve useless, and not available new anyways

Perfect, that is what I wanted to hear. Yes the diaphragm is not holding a perfect vacuum. Pretty much just a slow leak.

Thank you...close to running I will be on the road SOON :-)