Hi, my name is***** the car run fine after you get it running on 8 cylinders? Does this only happen after a hot restart?
For a cold start problem I would suspect a fault with the warm up regulator. The regulator lowers the fuel pressure to richen the fuel mixture when cold. If the pressure is too high it will run very lean until it warms up. I would suggest connecting a CIS fuel pressure gauge to the warm up regulator to measure the cold control pressure through the regulator. On a cold motor it should be around 2 bar. When the motor warms up the pressure should rise to about 3 - 3.5 bar. I would also check the spark plugs and wires and cap and rotor to be sure you are not getting a misfire when cold.
Sounds good, let me know if you need anything.