Hunting Idle

[ChrisBourk at aol.com]

In a message dated 98-11-01 14:15:56 EST, you write:

<< Any help with this would be appreciated...........I am working with a mild
MPFI 427 big-block project.  The engine and cam are fairly conservative,  the
induction system is from Accel,  the injectors are 30 #/HR SVO saturated
units, the computer is a 16197427 with BCC AUJP.   Despite much effort, we
cannot get a stable warm idle.  The idle speed hunts up/down excessively, and
the rush of air through the IAC sounds like a large household vacuum cleaner.
The IAC is responding to the computer.   With a carb,  the engine used to idle
nicely at 800 RPM with around 16 "Hg.   Learned IAC counts are about 40, and
current IAC counts swing wildly.  More throttle blade minimum airflow does not
seem to help much.
 
 Thanks. >>


Vacum leak???

Christopher