I could use some help, our John Deere 486 E seems to have a fuel problem, fuel pump is new in the last year and still seems to be putting out plenty of fuel to the injector pump, brand new fuel filter, have to give it some ether to start then will run with the pedal pushed about half way down but will not Rev up at all. I cracked the injector lines and this will cause a miss and there is a strong spray of fuel. I am thinking injector pump but don't want to spend the money unless I'm sure.