KMS MP25 - Page 19

KMS MP25(M)/MA25(M) manual Version 4.2
19
In the figure above, you can see an example of how different boost correction factors influence the
enrichment percentage and injection time. So, if the injection time in the complete injection table
is set at 10 ms and correction factor set on 1.00 the injection time increases with 10ms/100kPa
what results in an injection time of 20 ms at 200 kPa (1 bar boost) and 30 ms at 300 kPa (2 bar
boost). With the correction factor set on 1.25 this is 1.25 x 10 ms = 12.5ms/100kPa and thus giving
an injection time of 22,5 ms at 200 kPa (1 bar boost) and 35 ms at 300 kPa (2 bar boost).
Unregarded the correction factor the negative fuel enrichment (under 100 kPa) will always be at a
1:1 ratio.
So, if the engine runs on 50 kPa (0,5 bar vacuum) the injection value will be 50% of 10 ms = 5 ms.
TIP: Try to start the engine with the complete fuel map at the same injection time (4 - 12 ms
depending on the injector size) and the boost correction factor set on 1.25. Try to get the engine
running smooth with changing the complete fuel map (all cells at once) with positive or negative
percentage (using the edit menu). If lambda control is active and the engine is at normal operating
temperature you can start programming (the separated cells in) the fuel map with the boost
pressure (set) as low as possible. After the injection table is mapped at low boost, the next step is
to raise the boost level in steps to the desired boost pressure. Check your fuel correction again.
Now don’t correct the injection table with this percentage but correct your boost correction factor
with this percentage.
➢ Main Load is: TPS + MAP as pressure compensation for N/A engines
All the load tables included lambda target and correction tables are linked to TPS value. The
injection tables are compensated for the manifold absolute
pressure. Engines with standard manifolds often have
bypasses and/or solenoids for situations when extra air is
needed. This extra air isn’t compensated with fuel when
only linking to TPS.
The injection table (TPS v RPM) gets corrected with 1% per
1 kPa of MAP pressure offset from 100 kPa. So, if the
injection time in the complete injection table is set at 10
ms, the injection time decreases with 1ms/10kPa. What
results in an injection time of 7.5 ms at 75 kPa. If the
engine runs on 50 kPa (0.5 bar vacuum) the injection value
will be 50% of 10 ms = 5 ms.
This is used for N/A engines.
TPS + MAP as boost correction factor
-150
-100
-50
0
50
100
150
200
250
300
350
0 100 200 300
Manifold Absolute Pressure [kPa]
Enrichment [%]
Boost correction factor = 1.00
Boost correction factor = 1.25
Boost correction factor = 1.50