Here is the story. I got a 1986 Nissan Pulsar NX from a friend. The
emissions results back before it was taken off the road was:

Driving Hydrocarbons (HC): 71ppm (MAX: 314ppm)
Driving Carbon Monoxide (CO): 0.26% (MAX: 2.41%)
Driving Oxides of Nitrogen (NOx): 2655ppm (MAX: 3390ppm)

Idle Hydrocarbons (HC): 84ppm (MAX: 402 ppm)
Idle Carbon Monoxide (CO): 0.10% (MAX: 4.54%)

Then the car was taken off the road because of a shot carburetor (would
stall out and you'd have to pump the gas to keep it going), which i
rebuilt, and the car drives fine, except i can't really get it to idle
below 1000RPM (suppost to be at 650RPM). So i turned the idle speed
screw up to about 1000 RPM so i wouldn't have to drive with two feet.
Sometimes it stalls going around left corners, is this a sign of a low
float level?

Anyway here is the current results:

Driving Hydrocarbons (HC): 247ppm (MAX: 314ppm)
Driving Carbon Monoxide (CO): 8.56% (MAX: 2.41%)
Driving Oxides of Nitrogen (NOx): 127ppm (MAX: 3390ppm)

Idle Hydrocarbons (HC): 73ppm (MAX: 402 ppm)
Idle Carbon Monoxide (CO): 0.16% (MAX: 4.54%)

So driving hydrocarbons are up, but still below the max, driving carbon
monoxide is through the roof, and driving oxides of nitrogen are barely
there.

New spark plugs, dist cap, rotor, spark plug wires, pcv valve.
basically i want the thing to idle and pass emissions. so what are my
problems?