The FICD will perform it job when manifold vac is greater then 15 inches Hg. The important part of scoot comments are that engine, fuel and ignition have to be working in harmony with each other. If you don't have the valves adusted properly hot, if you don't have an engine's timing adjusted for the correct fuel, if the PCV valve isn't working correctly, etc. Which I would believe your personel have all looked at. There were two FICD devices offered which include with the vac piping and the delay valve play a part.
This is ONLY to be used to report flooding, spam, advertising and problematic (harassing, abusive or crude) posts.