North American Turbocoupe Organization

Full Version: What cools in tank fuel pumps
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The automotive in tank fuel is something that is a mystery to some as to how it works and does not self destruct. Its basically a small electric motor 12 Volts hooked to a pump. It sits in the bottom of an automotive fuel tank and produces anywhere from 15-70 lbs of fuel preasure depending on the injection system. It produces heat and must be cooled and provides fuel delivery fore many many years. It gets cooled by sitting in a pool of cool fuel and has a bypass system to keep this fuel cool and circulating to prevent vapor lock and rotor longevity on its pump portion and lubricates it. Basically most of us on this site have messed with or replaced one from time to time and never gave it a thought how it works. The pump must cool itself all the time. When the tank is full its no problem but what happens when the tank starts to empty? Well their is a little part in the return line that sprays fuel on the pump and fans out to a wide spray pattern. Its called a KAZOO. You know what it is its that little flattened out hose blue in color or orange some are green. This little part is crucial to the pumps life. When the tank runs low the spray cools the pump. Newer pumps are installed horizontally like my camaro and are installed inside a canister. Most newer cars have this encasement system to protect the the pump from heat. It keeps fuel around the pump for cooling. So with that said having a pump in the tank we must protect it. This can be done by not letting it come out of the fuel. Always keep at least 1/4 tank of fuel and no lower. When getting fuel let the pump cool down before refueling. The cold fuel hitting a worm pump can actually shock the pump and it can fail. I normally fill up with my engine running. My friends have different theories but that is another story. We discuss this stuff at the diner in the morning and its interesting at best. This is just my theory and others agree.Now i know the law requires engine shut down during refueling. Just wanted to share it with you guys. Thank you and have a good morning Gentlemen