Honda Civic Service Manual page 376

PGM-FI System
System Description (cont'dl
Lean Burn Control {D16Y5 engine: CvT)
The lean burn control system is based on the characteristic increase in crankshaft angular acceleration which occurs in
when the air-fuel ratio gets leaner.
The CKF sensor, which is mounted on the crankshaft, monitors sngine speed, lf crankshaft angular acceleration falls below
a certain level (target air-fuel ratio level), the amount of injected fuel is reouceo.
lf crankshaft angular acceleration exceeds this level. the amount of fuel is increased.
This system improves fuel economy and driveability by controlling the amount of injected fuel in the lean burn range
immediatelv before combustion starts to deteriorate.
1 1 - 1 0 6
TOC/CKP/CYP SENSOR
MAP SENSOR
CKF SENSOR
ECM
Comparison oI current air
fuel ratio to target ratio