I have a b18a1 in a 90 crx, using 91 teggy computer (virgin).

No check engine lights, and runs great when warming up, but once warm, the idle starts bouncing back and forth slowly between 750 and about 875. The air fuel is going rich and lean in harmony with the idle bouncing. When driving down the road, the air/fuel goes from rich to lean back and forth at an amazingly fast pace.

Any ideas?

I've reset my idle via chilton procedure
Cleaned out my EACV
Cleaned up and tightened the white scew in the fast idle thermo valve.
new oxygen sensor
Checked timing
Vacuum at 22, SOLID
No vacuum leaks that I can find, and everything is routed right.
Bled out the coolant like 10 times.

Still having the same problem. Any other ideas?

 

take out your fitv; take it apart and thigten the white plastic screw thats in there.

As far as your AF gauge, the sweeping up and down its normal. oits the ecu ''checking'' with the O2 in closed loop