i a running a 255 walbro intank pump. it started breaking up and puttering on low end. i thought it to the local dyno my air fuel started at 16:1 came down to 13:1 then went back up off the chart then jumped all over the place not staying steady or even coming down close to rich. i've tried a fuel pressure test at idle it makes40psi as soon as i hit the throttle it goes down to about 35psi...maybe bigger pump :confused: ?