To operate the manometer the PVC pipe was filled with colored water...
Then the ruler was positioned at the top of the water column.
One of my favorite sites for fuel injection information is Ramjets that Run at http://www.jerrybramlett.net/index.html. Jerry Bramlett talks about cold start cranking vacuum and states, "Only .5" to .7" water vacuum is needed at the main diaphragm during cranking to generate a good fuel stream at all nozzles."
So, in conclusion, since we only need .5" to .7" water vacuum and we have 3.5", I guess we need to look elsewhere for our cold starting problem. Next we will investigate the high pressure fuel pump at low RPM. Stay tuned.