In a message dated 6/14/00 7:45:21 PM Eastern Daylight Time,
geoffrey.hausheer@intel.com writes:
> I understand this, but I thought the whole point of closed-loop mode was
> that the computer watches the O2 sensor, and cuts back the fuel to keep it
> running at the right A/F ratio.
When in closed loop, the PCM will note a rich or lean condition and
store a number to be used in the fuel calc for that RPM & MAP
range, but it is a move in the right direction, not a "cure-all" for
installing oversized injectors. The intent of the learn function is to
fine tune the inj pulse width, which "should" be very close to start with..
If you install bigger injectors and rely on the computer to take up the slack,
you'll still be on the rich side, just not as bad as in a "no learn"
situation. Also, the vehicle will be running in open loop
before warmed up, and will be running rich at that time.
Because of the deminishing returns provided by raising fuel pressure,
you can use that logic in reverse and lower the FP a little to get the
mixture correct at low puls widths (idle) with you larger injectors,
and you will still end up with greater fuel flow when the pulse width
goes up, when compred to the stock injector with normal FP.
Sorry if that was clear as mud.
Cheers,
Mike V
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:51:46 EDT