I've been printing loads of various test pieces experimenting with different custom settings to find the best setup.

I'm fairly happy with things so far using grey ABS and white ABS.
Whatever I try with Yellow ABS, the layers will not bond. The print LOOKS fine, but has no strength and every layer delaminates with very little force.
I've tried a whole range of temeperatures speeds and layer heights but cannot get the layer to bond.

The filament came from the same place as the Grey and white which work fine. I got them from the supplier of the printer (Technology Outlet) he said he gets them from Holland not from Flashforge.

Any ideas? I've also tried drying it out in the oven at about 60deg for half hour. Made no difference. But as I understand it, ABS does not absorb moisture to any significant extent anyway.