Newbe here!

[Tom Hussey]

Hi Scott,

The ECM I am working on might be the same as your '96. I have been
working through it with the idea of enhancements for power and throttle
response. 

> I wonder if I couldn't
> get a little more out of the system by modifying the way the PCM reads
> their values though.
It is my understanding that the mixture is enriched at WOT to the point
where some power is lost. I have worked through some but not all of the
code relating to the O2 sensors but have no thoughts on modifications
just yet. I have found the spot in the code where the diagnostic can be
turned off. I don't think this will help much because the system will
then consider the input as good and use it in calculations. I expect to
complete my project next winter because race season starts next week and
there won't be much time this summer :-)


> After
> I collect the rest of the equipment (PROM blaster/reader etc.) I will
> be
> more able to give input.  I do have some input on a couple of posts.
The '96 should have FLASH and not need a prom programmer. Just now I am
looking for the download&execute code in the OBD and should have info
for everyone soon.
> 
> 1. As far as the anti theft systems go the PCM only looks at the "fuel
> enable" input on start up. The board I used to bypass it produces a
> 30Hz.
> waveform. It doesn't seem to be too critical as I have run it as low
> as 25
> and as high as 40. The only condition seems to be timing. I found if I
> triggered it with the starter it seemed to work nearly flawlessly.
> Maybe the
> signal is just dirty enough that the PCM accepts it.
Yup, a 555 timer is all that is needed to enable the ECM.

> My experience is a factory MAF will work up to
> about 400 rear wheel horses. It pretty well simplifies the MAP sensor
> problem. Has anyone considered adding a second MAF or a Callibrated
> bypass
> to allow more airflow while maintaining readings at higher power/RPM
> levels??
There have been several suggestions as to what the stock MAF is capable
of. In addition, there is code inside the '97 ECM that tries to make
sense of the MAF reading as it relates to throttle, RPM, temperature and
so forth. The ECM uses these to determine a range it expects the MAF to
be in and lights a code if it is outside the normal. As usual this is
sampled a number of times before the MIL is commanded. I have had a few
ideas about this similar to what you suggest. I feel the real answer is
to re-program the acceptable range to match the new cam.
One thing I can tell you is that there is a TON of code for the auto
trans. That thing is big time complex. There are all sorts of adaptive
routines as the ECM constantly updates solenoid timing for shifts to
reduce slip. Lots of code relating to torque converter clutch. I won't
be too much use there because as soon as I figure somthing is auto trans
related I set it aside (mine is an M6).

Good luck with your project and welcome to the list!

Cheers,
Tom Hussey