Closed loop/open loop @ WOT

[ext-peter.betts at nokia.com]

But I guess I would ask........ 

Whether the ECU uses the O2 lambda signal or not in open loop WOT it doesn't
stop a monitoring device displaying it's output, does it?

Does it still make sense open loop to read the sensor so a human can
determine if something has gone horribly wrong?

The ECU just uses a fixed (learnt or default) fuel setting (injector duty
cycle, probably near max) for WOT but won't the O2 sensor still indicate, if
in a modified car, the setting the ECU is using is running the car lean and
hence one needs to modify something else like injector size to compensate.

(Oh.. does the ECU learn a setting or do they normally just use a fixed
setting in open loop for injector duty cycle)

Of course in a ECU which is programmable one could change this setting but
some Toyota ECUs (Supra) don't allow reprogramming.

Pete



> Master of Disaster wrote:
> > 
> > I think you should sell your Supra and buy something American, with
> > an LT1 or LS1 engine. :^)
> > They stay closed loop at WOT, or thus I have been led to understand.
> > I am not bad-mouthing the Supra-- it's a beast, but if it goes open
> > loop at WOT, I don't want one.
> 
> Actually all LT1s and LS1s go into open loop at WOT.  Why 
> would you not
> want the PCM to go into open loop at WOT?  I guess it would 
> make tuning
> up there a little easier...
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