"Bernd D. Ratsch" wrote:
> Closed Loop is at idle and at cruising only. Startup, decel, and accel
> (including WOT) are Open-Loop operation.
I would have to further qualify those statements by saying that the decel and
accel conditions are normally also closed loop. Only in the cases where the
delta-tps and delta-map are great do we get open-loop operation. For example a
rapid accel (like passing a car) will cause a transition to open-loop but in the
normal case of gradually accellerating (or decel) - these are all closed loop.
The only reason I comment here is because at first read of your statements - it
appears that closed-loop operation would be a rare condition which is not the
case. In fact - the opposite is true - 95+ percent of the time EVERYONE is in
closed-loop.
Case in point - I have posted a scantool log of a trip I took recently. It
contains the output of every sensor reading, status of OL or CL, every few
seconds for almost 2 hours of non-stop driving. I counted like 13 transitions
(few seconds each) to open-loop. Adding up the actual time - I am left with
less than a minute of actual open-loop operation compared to around 2 solid
hours of closed-loop operation. The data supports my assertions.
The URL to the datafile is http://home.netcom.com/~smoseley/TOPICA3.DAT
(topica3.log, and TOPICA3.TXT are there also as I was not sure if the scantool
needed those as well)
The URL to the scantool used is http://www.obd-2.com
Anyone here can download the scantool from obd-2.com, install it, then download
the scan datafile at my homepage URL and make up your own mind as this is the
raw data from which I draw my conclusions.
If you step out of the box and think about it - this HAS to be true or else the
PCM really isn't controlling emissions and we know thats not the case.
Latr,
Shane
-- '96 IndyRam-HisIndy-MPI/TB/Pulleys/AccelCoil/MPComp/HookerSuperComps/CompTAs '96 IndyRam-HerIndy-numbered(#142)"Track Truck" '74 Triple-Black Dodge Challenger Rallye 360 home-brew EFI R&D vehicle '68 Black Corvette Convertible 427 (For Sale)
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:59:29 EDT