Mark Ferrari wrote:
> I dont know for sure, but my best guess is that the computer richens the
> mixture a bit at WOT to help with cooling.
It might have something to do with cooling - but I do know this: When running -
you are either in closed loop or open loop - I think everyone agrees on that.
Closed loop concerns feedback from the O2 as to what is ACTUALLY going on re:
Air/Fuel ratio (this is an EXTREMELY fundamental part of EVERY modern EFI setup
-and- most here just can't quite grasp this concept) When in open loop - there
is no feedback - therefore, assumptions have to be made about what kind of
fueling (and timing) strategy to deliver to the engine under whatever conditions
(determined by the other sensor outputs). This is done by reading tables and
using the sensor outputs as indexes to these tables.
The main reason for the overly rich condition is because the manufacturer would
rather error on the RICH side as opposed to the LEAN side of Stoich (14.7).
Thats it in a nutshell...
Latr,
Shane
ps - I don't understand why this is so hard for most to believe. I have stated
it here about 30 times without so much as 1 single piece of evidence to the
contrary. It even applies to ALL engines - whether 8cyl, 6cyl, 4cyl,
motorcycle, airplane, etc... Has anyone ever heard of "control systems"???
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This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:59:53 EDT