If it has been running fine after starting and your mileage is decent I would say the coolant sensor to the ECU is good.

Intermittent fail to start but cranks are symptoms of the Fuel Injection System Relay, first. It is located behind the glove box and is white in color.

A change in temperature affects the board material of the circuit board, copper coil wires or even the contact fingers. Just about all, that is in there. In addition, check the connector it plugs into. Give it a peek for corrosion or loose tightness onto the relay terminals.


Most people get another one (new or P-N-P) and keep the repaired (soldered) one as a spare, as they seem to fail more often than fuses. For some strange reason, there is a spot in the fuse panel to keep those.
The relay is not in the most convenient place but you can reach it from underneath after you remove the felt underpinning.

Hope this helps,
Phil