I've pulled injectors out of engines since the late 70s. I have never seen such dirt until I pulled the ones out of my tour. I guess the moronic design that kruds up the UIM/LIM dirtys up the tips on mine. Then we have deposits left behind in the injectors from the poor quality of the gas. Who knows what is in todays gasoline in the way of cleaner. When I worked at Gulf Oil many years ago I used to read the random test reports the states performed on gas stations. Some were hidious! Some of the off brands added octane boosters that ate up fuel system parts. They did this to meet the state requirement for octane - screw the public.
