1977 280Z 5spd is failing the CA emissions test for both HC and C0.
The 5 & 6 cylinder plugs appear to be running much richer than 1-4 due to black soot on these two plugs not found on the other 4.
Compression reads between 130psi and 135psi across all 6 cylinders.
I have replaced the plugs, plug wires, rotor, distributor cap, coil, fuel filter and EGR valve.
I ran through the "poor mileage" xblshooting section of the 280z service manual and everything passes except the air regulator DC voltage check.
A. A continuity check at the sensor on the air regulator tests good.
B. When I initally pulled the vacuum lines from the regulator I could see the valve was 1/2 open. After running the car, I pull the vacuum lines and the valve
is closed.
Looking through the fuel injection bible pdf on page 56 Test #1 - (8) there is a part labeled "Relay". Where is this physically on the car?
I am looking for where and how to adjust the air fuel mixture, but I have yet been unable to locate a mixture adjust screw or instructions on the suggested means to do so. Any input or guidance on the where and how?
Thanks,
Troy