I just got the new pressure washer from Home Depot today. When i start it up it idols fine, but when you press the nossel to start spraying the water the engine runs high and low. Its like up down up down up down up down......I see the choke moving back and forth every second or so. It still sprays fine but it eventually acts like it once to die on me. I did find that the fuel line where you can squeeze it to prime the fuel was cracked. I replaced it and thought i fixed it cause it ran much better. But after running about 5 min it started doing it again. It almost acks like its starving for fuel when it has to rev up, again it idols fine. I do hear backfiring once in awhile. Model is RD80702 and it has the fuel injection on it a 2009 model. Any ideas?