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> Engine > Fuel Control > Power Enrich
Power Enrich Fuel
Power enrichment tables are used when the VCM detects wide open
throttle (WOT) operation and provides extra enrichment to achieve
maximum power.
Note: A working, calibrated and correctly positioned wideband O2
sensor is required to tune engine fuel requirements. Excessive lean
conditions due to incorrect use of these parameters could lead to
severe engine damage.
PE Enable
- Enable MAP: This MAP value must be exceeded to enable PE
mode
- Enable MAP Hysteresis: This value is subtracted from the
enable MAP value. If the MAP reading drops below this value then PE
mode will be disabled.
- Delay RPM: PE mode is delayed if RPM is below this
value. Set to 0 to disable PE Delay and enter PE mode
immediately.
- Enable RPM: This RPM value must be exceeded to enable PE
mode
- RPM Hyst: If enabled, RPM value must drop by this amount
to disable PE mode
- Enable Torque %: Percent desired torque required to
enable Power Enrichment
- Torque % Hysteresis: Percent desired torque hysteresis
for disabling Power Enrichment
PE Enable TPS vs. RPM
- Hot Power Enrich Enable %TPS Threshold vs. RPM: These
tables defines the minimum TPS% vs RPM that the VCM requires to
enter WOT and is required to enable PE mode. There are two tables
labeled Hot and Cold that allows different thresholds depending on
whether the coolant temperature has exceeded the Hot Select
temperature (see below). If the coolant temperature exceeds the Hot
Select temperature then the Hot table is used, otherwise the Cold
table is used (not available on all PCMs).
- Cold Power Enrich Enable %TPS Threshold vs. RPM: These
tables defines the minimum TPS% vs RPM that the VCM requires to
enter WOT and is required to enable PE mode. There are two tables
labeled Hot and Cold that allows different thresholds depending on
whether the coolant temperature has exceeded the Hot Select
temperature (see below). If the coolant temperature exceeds the Hot
Select temperature then the Hot table is used, otherwise the Cold
table is used.
- Hot Select Temp: This value selects either the Hot or
Cold TPS threshold table (see above).
- TPS vs. RPM: This table defines the minimum TPS that the
VCM requires to enter WOT and is required to enable PE mode.
Power Enrichment
- V8 Power Enrich Fuel EQ Ratio vs. RPM: This is the main
table that is used to tune WOT fuel. The values in this table are
Equivalence Ratio's (Fuel/Air multipliers or AFR divisors) ie.
values greater than one are richer, values less than one are
leaner. The values relate directly to the Stoich AFR and the
resulting commanded AFR is Stoich divided by this PE equivalence
ratio. Eg. if the multiplier is 1.1 then the commanded AFR will be
14.7/1.1 or 13.36.
- V8 Power Enrich Fuel EQ Ratio vs. RPM (Alcohol): This is
the main table that is used to tune WOT fuel for post 1999 V8
engines. The values in this table are Equivalence Ratio's (Fuel/Air
multipliers or AFR divisors) ie. values greater than one are
richer, values less than one are leaner. The values relate directly
to the Stoich AFR and the resulting commanded AFR is Stoich divided
by this PE equivalence ratio. Eg. if the multiplier is 1.1 then the
commanded AFR will be 14.7/1.1 or 13.36.
- Power Enrich Fuel Adder vs. Coolant Temp: This table
adds to the PE multiplier (above) in relation to engine coolant
temperature (ECT).
- Power Enrich Fuel Adder vs. Intake Air Temp: This table
adds to the PE multiplier (above) in relation to inlet air
temperature (IAT).
- V6 Power Enrich Base vs. ECT: This table sets the base
AFR for Power Enrichment on V6 engines. Note this is an AFR value,
higher is leaner.
- Power Enrich Fuel Adder vs. Throttle Position Sensor:
This table adds to the base AFR in relation to throttle position.
It is generally used to lean the fuel at smaller throttle
settings.
- Power Enrich Fuel Adder vs. RPM vs. Time: This table
adds to the base AFR in relation to RPM and time in PE mode. It is
used to provide additional RPM and time based enrichment and is
similar to the PE vs RPM table on V8 engines, but with an
additional time component. Remember, this value adds to the Base PE
AFR so positive numbers here are leaner and negative numbers are
richer.
- Enrichment Rate: This is the rate at which Fuel is added
to reach the desired enrichment value. The smaller this value is,
the slower the VCM will reach the desired PE AFR. For instance if
your non pe commanded EQ ratio is 1.0 and your pe commanded EQ
ratio is 1.300 and your enrichment rate is set to .3 it would take
1 step ~10ms for most pcms to reach full PE.
- Base AFR vs. ECT: This table sets the base AFR for Power
Enrichment on some I4/5/6 engines. Note this is an AFR value,
higher is leaner.
- Base AFR Mult vs. RPM: This table multiplies the base
AFR for Power Enrichment on some I4/5/6 engines in relation to RPM.
Numbers less than one will lower the AFR (richer), numbers greater
than one will raise the AFR (leaner).
Boost Enrich
These values are for 2bar or 3bar Speed Density packages.
- Boost Enrich: This table is an Equivalence Ratio (just
like the PE table) and referenced to MAP. The PCM will use the
richer of this table and the PE table to determine fueling. It is
useful for some supercharged and turbocharged engines where boost
does not always correlate to RPM.
- Enable MAP: This is the minimum MAP to enable the Boost
Enrich table. Additionally, above this MAP the engine will enter
open loop.
- MAP Hysteresis: This is the MAP hysteresis to disable
the Boost Enrich table.
Piston Protection
- Enable RPM: RPM must be above this to enable Piston
Protection (fuel enrichment) mode. Set to maximum to disable.