I used to work in fuel storage and delivery for one of the big car manufacturers and then its component offshoot.
Colleagues and I spent a lot of time trying to get the management conscious of the development and component work needed to get diesel and biodiesel systems to work 'transparently', i.e. like gasoline systems. A lot of the problems came from serious misunderstanding of the range of qualities of diesel and biodiesels.
What you do need is/are:
1) a heated filter assembly (Stanadyne, Bosch + others)
2) a recirculation from the FIP outlet to the line from the filter to the FIP (uses the heat from the previously compressed fuel to warm the inlet fuel)
3) a thermostatic valve to redirect fuel down the return line once the temperature is much above 30degC (Bosch)
4) fuel line heater tape/wire and thermal insulation (
info)
5) the return from the engine going right close to the fuel pick-up in the tank (SAE papers have info)
6) the fuel pick-up in the tank preferably being via a fuel delivery module, where a jet pump on the return line entrains tank fuel into a mixing reservoir with return fuel so the pick-up fuel is warmed. (SAE papers and patent publications have info)
Having put all this work into getting a reliable delivery system for diesel/biodiesel, you then have to be careful in hot weather.
In my development work on a 2.5l 100bhp turbocharged, non-common rail engine (Bosch VP44 pump), fuel injection pump inlet temperatures of over 90degC were experienced on a rolling road test at vehicle max speed, with simulated road speed air movement. Too much of this causes metallurgical failures of cams and plungers in the FIP. Then you seriously need to chill, as they say.
Bill