Smart 451 1.0 12v hard to start and rough idle.

Hey guys.
So I'm having a few issues wondering if you guys can help. I picked up a 451 gasser with a blown head gasket it had hard starting issues and rough idle. Here's a list of things I have changed.
Head gasket
Timing chain
Water pump
Spark plugs
Starter
Things I've checked
Vaccum leaks
Purge valve
Swapped coils around
Swapped injectors around
It will start fine if put your foot on the fuel pedal...that's telling me its rich...correct me if I'm wrong. One code popped up once and it was bank 1 rich at idle..
I'm really stumped on this one. I can find my fuel pressure tester adaptors so I ordered a new one so I can check fuel pressure. Other then that I'm not sure what else to check? Car has great power not sluggish at all just the starting and idle issue Any help would be greatly appreciated!