I noticed the vacuum hose to the distributor was lying on top of the exhaust manifold shield, and and the underside was damaged. I replaced the hose and now my idle is way too high, I can't seem to adjust the idle screws as they are already all the way out...i'm guessing the previous owner adjusted the timing based off of the none working vacuum advance. Is there something I'm missing here related to '73 e type series 3 V12?

 

Don't know much about the V12 but I assume the disconnected hose caused a large vacuum leak that required an improper idle mixture adjustment. Now it is running rich. Timing and mixture should be adjusted per instructions in shop manual or by a good mechanic.

 

Are you sure you have it connected to ported vacuum, rather than manifold vacuum?

 

I just reread your original post and noticed you said the screws were turned out. Out (counter clockwise) raises the idle speed. This is probably a wording issue but thought I would point that out, just in case.

 

I ended up disabling all 4 Stromberg temperature compensators, this fixed my problem, I reconnected the vacuum advance which is connected to manifold vacuum and adjusted both the idle and throttle sync (hiss) as per user manual. I've ordered the XKE.com shop manual and a couple of Stromberg synchronizer tools, I'll fine adjust when they come in. The car runs fantastic now idles around 750rpm and jumps to attention on start.