93 Civic hatch running rich

[Umby]

I've got a 93 Civic CX.

I recently dropped in a JDM ZC motor (D16A6).

The car runs great and my fuel economy still seems normal but over the last 3 or 4 days I've noticed a small puff of black smoke at high rpms or under strain and my tailpipe is collecting a pretty fair amount of soot.

In the last 5000 miles its had fresh NGK plugs and NGK wires, new cap and rotor, and a new fuel filter.

I haven't pulled the plugs to check them yet but as of 2 weeks ago they looked like they were burning perfectly.

The car is running on the factory P05 ECU and has the one-wire o2 sensor.

I'm not getting a CEL and the ECU isn't storing any codes.

I haven't taken it for emissions yet this year so I'm not sure what my levels are.

What are some things that could be causing this?

[Theycall_Metue]

oil ring

[Umby]

If you mean psiton ring that's not it. Compression is good and it doesn't comsume a drop of oil. Oil smoke is blueish in color and leaves more of a greasy film(as a Mitsubishi owner you should be well familiar). Something is causing the car to load up on fuel under strain but I don't know enough about how Hondas process information to start troubleshooting.

[Theycall_Metue]

theres 3 rings, oil ring and 2 compression ring. if the oil ring is bad, oil is getting into the combustion chamber and burning leaving black smoke ( more noticeable at high rpm)

blueish i think is running rich? or lean?

Mitsubishi burns oil yes, but most are not noticeable like in the eclipse i use to own

[Umby]

Blue smoke is oil. Black smoke is carbon being created by an excess of unburned fuel. My car is running rich at high rpm... Not burning oil.

[Barefoot]

what ecu

[Theycall_Metue]

nvm

[Umby]

nvm

Whatever man

[Umby]

P05

[Theycall_Metue]

no you were right
rich = black
oil = blue

but you said your running rich