Test your flame heater nozzle in a clear plastic bottle to verify the spray pattern. If you have an extra intake manifold, test the whole thing as shown in the image here.
During the test shown below, I noticed that the flame is easily snuffed out by the forced airflow (from the turbo), which uses a more narrow manifold (the picture shows the N/A engine manifold), which prompted me to make a "flame detector" with a pilot light to indicate a flame, but that's another story.
Bottom line is that the N/A intake manifold with slower airflow seems more reliable than the turbo manifold.