I'm looking for info on the fuel pump assembly on a 2001 Chevy Blazer 2dr. How it works and such. Why is there two nipples on the bottom of the fuel pump? And why is there two strainers? One on the outside of the canister and one on the bottom of the pump inside the canister. Would like to know how the fuel flows through all the passages built into the canister. Any help would be appreciated.