Two things I agree with PaulE because #10 aeroquip pickup lines will swell duer to heat of fuel. Fuel pressure on a 3406E should be about 80 PSI and hold steady when shutoff. The only wat to check is pull line off and visually l;ook in the line. Second Boost since it is computer controlled can be tricky to gauge by, I would find a good CAT man who knows how to adjust ypour overhead and see if that helps.