Temperature Related Starting Problem Uk

[NickSw]

Hello. I first posted this problem about a month ago.

Since then I have changed the fuel filter and fuel filter housing/lift pump. Also changed the Battery for a slightly higher a/h thing.

The exstant filter was clear of any water or contaminents. I changed the fuel filter housing/lift pump assy just in case there was either a hairline crack in the assy or the lift pump was goosed.

Since then the little car has started first and every time, temps in that time have been little above zero.

Until today when the weather has again turned a little inclement and temperatures have dipped below zero once more.

Today it would not start, after several attempts.

Checked the plunger on the fuel pump and it felt slack. After several pumps some firmness was felt. This appears to indicate that fuel is draining back from the pump/filter to the tank.

Why should this only be evident in sub-zero temps?

My suspicion is a sensor (malfunctioning) that does something to the fuel system at such temps.

Any ideas please?

Many thanks,

Nick