Posting for a buddy of mine having a problem. He's running a electric Holley Blue pump with dual tanks, picking up fuel from one tank or the other depending on pit cock direction. Seems that the fuel is struggling to deliver. On idle motor runs up then down to the point of dieing, give it some pedal and it stays running.... It's a slow up and down probably 30sec. Intervals. I know these electronic pumps are better for pushing and not pulling, but my Holley Black works fine on my boat... Couldn't tell if it was carburetor issues being that the boat would barley idle. Any suggestions ? Thanks