Still not 100% sure about our problem with our E350 that I have previously posted questions about. Because of the weekend, the mechanic will continue checking it out today. He is saying now that it may be the fuel pump which is in the tank. The fuel filter was very dirty (greasy). Is there just one fuel filter on these trucks? What kind of time and money might we be looking at if we need to replace the fuel pump? The mechanic will most likely be doing it. Could the dirty fuel have clogged the injectors and if so, how are they cleaned? Again, thanks for your help.