Holley COMMANDER 950 User Manual

Page 40

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40

DOES THE

ENGINE HEISTATE OR

STUMBLE?

RAISE LEFT 6 BOXES

OF THE

“Rate of Change of MAP

Sensor”

TABLE 10 UNITS*

YES

* Most of the time, fuel pulse

width needs to be added to these
tables if the engine doesn’t rev
smoothly. A lot of fuel needs to
be added before the engine
stumbles due to too much
fuel.
As always, if the symptom gets
worse, try taking fuel out. Spark
advance can also have an effect.

ACCELERATE AT A

MEDIUM RATE

Note:

This flowchart is slightly simplified. See
accompanying text for details.

GOOD! MAKE

ANOTHER RUN TO

DOUBLE-CHECK

TUNING. THEN

PROCEED TO HIGH

LOAD TRANSIENT

TUNING

YES

RAISE LEFT 6 BOXES

OF THE

“Pulse Width – Rate of

Change of TPS”

TABLE 0.3 mSec**

DOES THE

ENGINE HEISTATE OR

STUMBLE?

ACCELERATE AT A

MEDIUM RATE

NO

NO

**

Avoid making too much

change to the TPS enrichment
table, as this will affect low load
transient response. Concentrate
the most on the MAP
enrichment table, as this has the
most affect on medium load
transient response.

Figure 21 EFI Tuning Guide—Medium Load Transient—After Base Map is Fully Tuned

GOOD! MAKE

ANOTHER RUN TO

DOUBLE-CHECK

TUNING.

DOES THE

ENGINE HESITATE OR

STUMBLE?

* Most of the time, fuel pulse

width needs to be added to these
tables if the engine doesn’t rev
smoothly. A lot of fuel needs to
be added before the engine
stumbles due to too much
fuel.
As always, if the symptom gets
worse, try taking fuel out. Spark
advance can also have an effect.

YES

NO

FLOOR GAS QUICKLY

(DRAG RACE LAUNCH)

RAISE RIGHT 10

BOXES OF THE

“Rate of Change of MAP

Sensor”

TABLE 10 UNITS*

Note:

This flowchart is slightly simplified. See
accompanying text for details.

Figure 22 EFI Tuning Guide—High Load Transient—After Base Map is Fully Tuned

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