Starting and Fuel Pump problems 1.9D

[Nicepix]

I've had difficulty getting the old girl to start in sub zero conditions. It starts OK when the air temp' is above zero, but when below it has to turn over for up to a minute to fire and run regularly. I had some new glow plugs fitted recently to try and resolve the issue. But it is still the same.

A second and possibly related problem is that from a few months ago occasionally the van would fire up OK and then stop after about 10 seconds. It took a lot of turning to get it going again. I checked the fuel filter primer and after an overnight rest the button needs about 15 pushes to become firm. I've been priming it every morning for the last week or so just to ensure that it goes from the off and keeps running.

Any suggestions would be welcomed.