So how do I tell if I have air in the system? The bowl is solid fuel and never an air bubble, even with 1/4 tank and bouncing through the food plot.
Air in the fuel can come from a loose fitting or filter.
We often see air getting into the fuel from a loose fitting, you would think fuel would leak out from the loose fitting, it would if the fuel was under pressure but because of the vacuum from the injection pump it pulls air in instead of the fuel leaking out.