Mechanical fuel pumps don't need a return line. They hold pressure and will not flow anymore fuel if none is needed. No hose is going to burst or anything like that. Pull one apart and you will find why. The mechanical lever does not pump the fuel, it ust pre-loads the spring. The force of the spring on the diaphram is the only this that pumps the fuel.
I am running a electric fuel pump, to 2 sidedraft Solex carbies. I don't have a return line or a pressure regulator, and it runs fine. I have had a regulator, but it made no difference on any setting, or without. So maybe the pump is running the right pressure and the needle seats and floats are working ok. Or maybe the carbs are flooding and the whole setup is too crude for me to notice? Runs ok, ecconomy not too bad.
New Toyotas do not have a fuel return line anymore. It's to do with emissions. Warm fuel vaporises and creates more emissions, so with no return line the fuel in the tank is left cold.
Mon, 07 February 2005 12:40
