Car is '96 Integra running a '95 JDM B18B, OBD-I. Has S-AFC installed.

Symtoms:
1) hard to start in cold weather (below 10C). Need to give a part throttle when cranking to start it up. Once started, car stays on and idles steadily.

2) Intermittent CEL on, mainly when it's cold outside. CEL code indicates TPS problem.

3) When CEL on, car sometimes get throttle cut-off and on for split second while coasting with about 10-20% throttle, esp in 2nd or 3rd gear.

Checked:

1) No vacuum leak on all hoses

2) S-AFC sensor check has no throttle position dead spot and reads normal for the TPS.

Any idea what's causing this problems?