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Should I worry about this?

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Old Feb 17, 2006 | 02:43 PM
  #21  
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Originally Posted by white2001s10
When did the PCM start feed-back learning mode during WOT?
or did I miss that memo?
Okay now you are Mr Funny? LOL. Does the computer respond to what the 02 sensors pick up? I know the system goes back to set program at WOT. If yes - Then they are FEEDING BACK information to the computer? If No then my post is inaccurate.

Last edited by Macon; Feb 17, 2006 at 02:54 PM.
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Old Feb 17, 2006 | 03:11 PM
  #22  
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I'm not the expert on the code, but to my knowlege the PCM applies only positive corrections during WOT, but is not in learn-mode during WOT.
If that is true then the PCM should never make any corrections based on WOT operation, though whatever corrections are stored in the highest load-cell will be applied if they are positive corrections.
That means that the PCM never knows if you are using N2O or not, based on O2 inputs.
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Old Feb 17, 2006 | 03:33 PM
  #23  
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Originally Posted by white2001s10
then the PCM should never make any corrections based on WOT operation
That I agree with...
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Old Feb 17, 2006 | 03:39 PM
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i think the only thing the computer can do at wot is pull timing due to knock. Not certain but remember something of that nature.
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Old Feb 17, 2006 | 08:49 PM
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The question i think was RPM swing upon shutdown.This is in part due to a rich A/F
Thus the 02s and P.C.M.adjusting for fueling needs.
Hawk
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Old Feb 18, 2006 | 02:32 PM
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Originally Posted by 227Hawk
The question i think was RPM swing upon shutdown.This is in part due to a rich A/F
Thus the 02s and P.C.M.adjusting for fueling needs.
Hawk
I thought that's what we just went over; that the PCM isn't going to be adjusting any fuel at WOT, so fueling wouldn't change when you close the throttle. The only source of extra fuel is the wet N2O system.
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Old Feb 18, 2006 | 11:23 PM
  #27  
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Originally Posted by white2001s10
I thought that's what we just went over; that the PCM isn't going to be adjusting any fuel at WOT, so fueling wouldn't change when you close the throttle. The only source of extra fuel is the wet N2O system.
And as I understand it now...it has to be leftover in the intake manifold to be a factor at that time...i see where all this is going/went.

Is there a chance that something like simple engine temperature and the fact that the motor has just gone through a more generally viloent state than it's normal operation and that is causing some short term idel fluctuation...
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Old Feb 19, 2006 | 11:11 AM
  #28  
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Well, it never happens with dry systems.
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Old Feb 19, 2006 | 09:29 PM
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At wot the pcm uses goes into WOT Power Enrichment Mode, using PE fuel multiplier. The 02 sensors are out of the picture, other than just reporting a/f. One thing that can have an effect on wot a/f besides the above, is if your running positive Long Term Fuel Trims, they will be added to PE multiplier and often lead to a rich condition. Now, if your running negative LTFT's then they are dropped. This is why when tunning ltft's it is rec to get them into the negatives, then they have no effect on wot a/f. However, when running a dry hit, having positive fuel trims can be helpful, as this will richen your wot a/f. don't forget the IAT vs Fuel adder, this can add another multipier to be added on top of your wot PE multiplier, for spraying a dry hit to richen things up.

Here is the two modes.
OPEN LOOP: operating without input from 02 sensors ie: cold start and wot
CLOSED LOOP: adjusting a/f acorrding to 02 sensor input ie: for all part throttle a/f, to keep it at 14.7 stoic for emmissions and fuel mileage.
Robert
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