Bad or Good Fuel Distributor ?

[ioang26]

560 SL
I purchased a used Fuel Distributor from EBAY,installed it,pressed the air plate before connecting the injector lines and fuel flows from the ports .
Connected all injector lines and started the car. It started OK with a some shaking and keeping about 750 rpms.And it was responsive when accelerator applied, it would rev nicely.

As soon as it reached the normal working temperature ,I pressed on the gas again and it bogs down and it dies.If I press it very slowly eventually it would rev but with trouble.

What is happening here? Any suggestions?
Is the FD bad ?