Aajaynefour@cs.com wrote:
> Well, I finally got around to installing it yesterday and I am pleased with
> performance gains :) However, I have a couple of questions.
>
> 1.) If OBD II is in closed loop and is getting all of it's computer input
> from the O2 sensors, the how does the IAT sensor (or driver adjusted pot)
> have an effect on the fuel system? Does the computer still receive some
> input from the IAT in closed loop?
I can answer that one - the IAT output is used during almost all modes of
operation of the PCM. Even when in closed-loop. When in closed-loop, it is
true that the PCM ignores the IAT output when determining general fueling (and
timing) strategy afterall by definition it is using the control source, the O2
sensor. BUT anytime there is a change in TPS or MAP (load triggers), if the
delta is enough - then the IAT is used to calculate the appropriate enrichment
(pos or neg) to provide for smoother driveability. If the delta is too much
(cross some threshold) it will transition into Open-Loop for a short period and
then use the IAT along w/the built-in tables to calculate fuel/spark delivery.
The battery voltage and temp are also used under ALL modes of PCM operation.
They can vary the pulsewidth delivered in ANY of the modes as well.
> 2.) Do the temp. to dial settings you gave with the instruction sheet
> indicate the ambient (outside) temp. or the temp inside the intake manifold.
> If it 80 degrees outside and I set the dial at 12 o'clock, for example, is
> the computer going to think it is 50-52 degrees outside? Would it be better
> to set it at an even cooler setting?
That would be a Bernd question. What would be the ideal type of display /
adjustment?
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)
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