1993 Cobra Mass Air Meter!!!

Daggar said:

Yeah... I gotcha. I wan't concentrating too hard onthe numbers either. Just using them to illustrate a point concerning adaptive control.

I do think that your 12% figure is a bit shy. I remember reading a paper on EEC-IV internals that suggested that 20% was the max towards fuel trimming at the bottom of the duty cycle and it skewed to a lower percentage towards the top of the duty cycle.

I have no real way to confirm which of our sources are correct though.

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vristang said:

I don't suppose you remember what document that was do you?

I have 2 3" binders full of documents I have printed off, so I understand if you can't site the source.
I don't even know how many docs I have saved to the hard drive.

As I think about it the adaptive limit could have even changed at some point. Tighter emissions regulations and such

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Anything external to the EEC, which that tries to modify the desired air/fuel ratio (based upon data from a Ford test
engine – hence the name “base” Open Loop Fuel Table) in closed loop operation, will cause the computer’s Adaptive
Control feature to try to compensate for the change by writing correction multipliers to KAM that correspond to the
load level at which the out-of-tolerance value occurred. The Adaptive Control will also monitor how the engine is
responding to the way you drive and make adjustments. Your ET may improve slightly after several runs as the
Adaptive Strategy shifts from street driving to drag racing. According to Mike Wesley, this control feature can only
make adjustments in a range of 25% of desired values. Tweecer user Rick Wagner has data logged his car and found
that adaptive control only varies ±12.5% or 25% overall. Below are graphic representations of the Open Loop and
Wide Open Throttle air/fuel ratio “base” table for an A9L Mustang computer and a 95 Mustang computer.

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vristang said:

I think that answers the question Daggar.

I was speaking +/- 12%, and you remembered the 25% TOTAL.

You say potato, I say potato.
(that looses some of its impact in written form )

jason

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srothfuss said:

My car as it stands right now is rich @ idle and fine in the middle and upper RPM's. If it was lean at all I can not tell but I am not using any type of AFR meter or other devices other than my smell and touch. Other than the transfer function being off the car "seems" to run better than ever.

But like I said before, I'll know more about the AFR after Monday.

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