Holley COMMANDER 950 User Manual

Page 49

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49

GOOD! START THE
ENGINE THE NEXT

MORNING TO

RECHECK

SETTINGS**

DOES THE ENGINE

STALL IN THE FIRST 2

SECONDS?

YES

INCREASE

AFTERSTART

ENRICHMENT 5% AT

THAT ENGINE TEMP*

ADD 5% MORE

COOLANT TEMP

ENRICHMENT AT

THAT ENGINE TEMP*

DOES THE ENGINE

STALL DURING

WARMUP?

NO

NO

* The actual amount of fuel that

needs to be added depends upon
how far the settings are off.

** The settings may need fine

tuning as varying cold start
conditions change (summer to
winter, etc.)

START THE ENGINE

YES

DOES THE ENGINE

RUN ROUGHLY DURING

WARMUP?

NO

ADD 2% MORE

COOLANT TEMP

ENRICHMENT AT

THAT ENGINE TEMP*

YES

DOES THE ENGINE

CONTINUE TO RUN

ROUGHLY?

NO

YES

Note:

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

Figure 32 EFI Tuning Guide—Cold Start—After Base Map is Tuned Hot

Afterstart Enrichment - Afterstart enrichment is fuel added immediately after the vehicle starts. It is then taken out very
quickly. How much and how quickly is adjustable with tables in the software. Even after the coolant temperature
enrichment is properly set, afterstart enrichment provides and engine with more fuel for a short time that is necessary for
best operation. Like coolant temperature enrichment, how much afterstart enrichment needed has a lot to do with the
camshaft in the engine. Efficient, high vacuum engines with small cams need less afterstart enrichment than engines with
large cams and low vacuum at idle.

Figure 33 Startup Enrichment

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