Cold Starting Problems 1993 DT

I've got a 1993 306 xtdt which won't start easily (if at all now!). the car has done 95k miles and I have recently replaced all 4 glow plugs (bosch) and the heater relay, to no avail. The problem is bizarre because when the car finally starts, it runs perfectly and will start again beautifully, even up to 2 days later. Its after 2 days that the problems start. Initially the car fires, but not enough to start it and from then on, forget it. Maybe after 30+ minutes of trying and waiting, it finally starts firing more and more and then goes. Initially when it does start, there is a fair bit of white smoke, but I am guessing that this is just unburned fuel. I have tried pumping the fuel bulb before, also to no avail. Maybe something to do with the immobiliser, fuel/ injectors? Anyone know why this problem might be occuring after 2+ days only?

Any recommendations gratefully received

Thanks in advance
George

Hi mate i have the same problem - changed the fuel and air filter and put some stuff in fuel tank to supposedly clean the injectors. The only thing i didnt do was change the glow plug under the injection pipes - any ideas how to get to the thing???

I would also try testing that power is actually getting to each of your plugs using 12v bulb after disconnecting the wire going to each respective one.

andy