Stratified charge. Partial load

When the engine uses Stratified charge, in case of even performance (RPM and required load),  MSD80 performs tests of chemical efficiency of injectors, to ensure max even performance of the engine.

The principle of tests is similar as in Homogeneous mode and is described here.


Differences from Homogeneous mode:

a) the same as for Stratified charge/idle tests, the allowed “corridor” of injector flow-rate differences is wider, reaction – quicker;

b) test results are summed to results of chemical tests of injectors in Homogeneous mode – Homogeneous mode is considered as a “base” level, Stratified charge is built as its supplement.

Test results of Stratified charge chemical tests can be seen here: ../F5/Shift+F6/F5, the bottom part of the menu.

a) last three rows show live data of the tests (in mode, when MSD performs tests);

b) three rows above live data – reference values.

The result of these chemical tests – multiplicative type corrections: it’s used as a multiplier when calculating the opening time of injector in the mode of the partial load.

Although INPA displays allowed differences +/-0.29, for correctly working injectors this difference is not more than +/-0.05, which corresponds to the deviation of +/-5 %.

These tests indicate differences in chemical efficiency of the cylinder in the exact mode between Homogeneous and Stratified charge modes. At first, MSD80 performs chemical tests for Homogeneous mode, then – turns on the Stratified charge and performs tests repeatedly.

Results of these tests are reflected in live data of injectors: ../F5/Shift+F6/F1, 4-th till 6-th line.


When the engine performs in Stratified charge, live data of Stratified charge (4-th till 6-th row, multiplicative type adaptations ..F5/Shift+F6/F1) includes:

a) coding data (flow-rate) of each injector;

b) multiplicative type LTFT of whole bank (../F5/F6);

c) test result of chemical efficiency of the injector  in Homogeneous mode (relative values: ../F5/Shift+F6/F3);

d) test result of chemical efficiency of the injector in Stratified charge (../F5/Shift+F6/F5, last three rows).


The result of chemical tests in Stratified charge will indicate higher values (different from 0), if:

a) the injector has severe instability of flow-rate;

b) the atomization of the fuel, injected by the injector, is very poor.

Obviously, such multi-level measuring of basic parameters of the injectors is chosen, to even in unfavorable conditions (for example, short drives, changing parameters of the injectors) ensure max even performance of the engine. Or more exactly – minimal possible unevenness before balancing of the cylinder performance (finishing current tests).