Fuel Injection Quantity Control; Outline; Injection Quantity Calculation Method; Set Injection Quantities - Denso 4D56 Service Manual

Operation Section
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10. FUEL INJECTION QUANTITY CONTROL

10.1 Outline

This control determines the fuel injection quantity by adding coolant temperature, fuel temperature, intake air temperature, and intake
air pressure corrections to the basic injection quantity. The engine ECU calculates the basic injection quantity based on the engine
operating conditions and driving conditions.

10.2 Injection Quantity Calculation Method

The calculation consists of a comparison of the following two values: 1. The basic injection quantity that is obtained from the governor
pattern, which is calculated from the accelerator position and the engine speed. 2. The injection quantity obtained by adding various
types of corrections to the maximum injection quantity obtained from the engine speed. The lesser of the two injection quantities is
used as the basis for the final injection quantity.
Accelerator Opening
Engine Speed
Engine Speed

10.3 Set Injection Quantities

(1) Basic Injection Quantity
• This quantity is determined by the engine speed and the accelerator opening. With the engine speed constant, if the accelerator opening
increases, the injection quantity increases; with the accelerator opening constant, if the engine speed rises, the injection quantity de-
creases.
Accelerator Opening
Engine Speed
Basic Injection Quantity
Maximum Injection Quantity
Turbo Pressure Correction
Intake Air Temperature Correction
Atmospheric Pressure Correction
Low Corrected
Quantity Final Injection
Side Selected Quantity
Injector Actuation
Period Calculation
Individual Cylinder
Correction Quantity
Speed Correction
Injection Pressure Correction
Q001152E