Injection Quantity (IQ) defines how much fuel the ECU delivers per cycle. IQ is the bridge between torque model, rail pressure and injection timing, making it critical for both performance and emissions.
Visão geral
The ECU transforms torque request into fuel mass using airpath models, smoke limitations and protection strategies.
Controlled Signals
- Driver wish torque
- Air mass
- Rail pressure
- SOI and EOI maps
- Temperature corrections
Maps Involved
- IQ to Torque Conversion Maps
- Limitador de fumaça
- Temperature Correction Maps
- SOI Timing Maps
- Maximum IQ Limiters
ECU Logic Sequence
Torque Request → Airflow Check → Smoke Limiter
↓
IQ Calculation → Rail Pressure Check
↓
SOI/EOI Adjustment → Injection Execution
Calibration Objectives
- Correct torque model → correct IQ
- Stable rail pressure during transient load
- Clean emissions behavior
Calibration Strategy
- Always fix smoke model before raising IQ
- Increase IQ only if airflow and boost allow
- Correct SOI to avoid excessive pressure rise
Diagnóstico
- IQ deviation faults
- Smoke limiter activation
- High EGT under load
Best Practices
- IQ is not a “power dial” — it must match airflow
- Monitor EGT and boost during high-IQ tuning