I finally got my '74 1.8 engine started. Seems to be spewing white smoke Also, when I connect vacuum hoses to the decel. valve the engine stalls.
I wonder if I need this valve? also if I eliminate the valve I can't just plug the hoses because, again, the engine will stall.

I went through this many mon ago; When I removed the decal on my '75 L-Jet, we used rubber corks and inserted on into the plenum nipple and a second one into the boot orifice/nipple. And, removed the small vac line.

Sound like you may have an air leak there or on another connection. Be carefull; sometimes a hose looks good, or a Y connector is holding; but closer inspection/testing reveals cracks....

Can you post a picture of your engine bay?

Make sure that the hoses aren't switched.

Here is some picturesClick to view attachment Click to view attachment

Well, it's been many days and a lot of fiddling with ignition and fuel and i'm still no closer to solving my problem.
Car will only run when I disconnect the decel valve and don't plug the hoses.
Also, white smoke.

I'm a patient person but i'm just about at the end of my rope!