- Sep 5, 2006
- Chicago Area
The filter keeps crud out of the very finely machined and articulated injectors. That is it's main function. They are made large nowadays on FI engines, for long life, and to keep working well with some crud in them. By far, a bad pump will puke a filter more than a filter will puke a pump. I can not say that I ever knew of a filter that caused a pump to fail. Broken pumps get crud in the filter, for sure.