i blew air from the pump back to the line that went into the tank.luckey for me their was a rubber conection,well i blew it out into a container ,,rusty! also if there are any conections in the line from the tank and one is letting air in even a small amount will cause poor suction...try running some Lucas upper cylinder and injector additive,,,works great for cleaning up varnished carb....just a suggestion after you clean up the tank etc.
