I had something similar with mine. During winter it would fire immediately and then die. Try again and hold the gas down to keep the revs up for 30 secs or so then it would stay running on its own.
Turned out the CPR was massively over leaning, but the only way to know this is a fuel pressure testing kit for k jet. Stethoscope for D owners!
I know it looks and smells like it's running rich but the fuel pressure gauge will reveal a lot. Has your car sat for a long time at some point without being properly sorted?
When I got my car it had sat for a while, but it ran ok and started instantly, except during the winter when it would die straight away unless you held the throttle open for 30 secs or so. Took me 18 months to get there but every part of the the fuelling was wrong, except the distributor.
If your car has sat for ages, with hindsight from my limited ! experience, strip all of the fuelling out and have it rebuilt, you'll probably need new injectors, check the electrics to the fuel pump., to make sure it's getting the power it needs under an 8 amp load.