ECU question for the technically inclined...

Chris Pronios hpro@b-link.gr
Fri, 18 Oct 2002 08:13:56 -0500


The facts:

Stock Euro-speced SR20DE ECU from a car with CAI/Exhaust and S4 cams has
been sent to tuner for tuning.

On return, its behaviour (when compared with the stock ECU)was very
noteworthy:

1. Idle smoother and close to 1000-1100 rpm.
2. Car seemed to pull much harder throughout the rpm range.
3. Up top there was a very noticeable gain.
4. Rev-limiter removed (we never let the car go above 8400!!! rpm  as shown
on the instrument cluster).

This behaviour has been duplicated in another stock SR20DE when we
substituted the tuned ECU for the stock one. Without even allowing for a
"learning" period so we could do back to back comparisons between stock and
"tuned" ECU, there was definite improvement troughout the rev range and the
rev limiter was indeed somewhere above 8200rpm (if at all).

Now comes the tricky part!

We opened the ECU in order to pull out the chip from the daughterboard and
see what it contained. Well, there was a 40-pin connector soldered on the
ECU but NO DAUGHTERBOARD. Furthermore, the jumper on the back side that
needs to be "changed" for the daughterboard to work had never been touched
so we know that the ECU never worked off a duaghterboard located ROM.
Apparently the "tuners" for some reason soldered the connector there but did
not proceed in altering the CJ1/CJ2 jumpers. Still, the ECU IS DIFFERENT
than the stock one.

To put it more eloquently....  WTF???!!!???!!!???!!!????????

During a very close visual inspection fo the moded ECU, we found that the
only thing with visual evidence of tampering was the little metal thingy on
the right of the 84-pin CPU chip.

I have posted this message in sr20deforum.com and nissanforums.com since
they allow posting of images for the lazy types but the an image with the
thingy indicated by a red arrow (in a stock ECU but the compenent is shown)
can be found at:

http://www.depa.gr/~1/ksanthou/image46b.jpg

or at the threads in aforementioned forums:

http://www.nissanforums.com/showthread.php?s=&threadid=7404
http://www.sr20deforum.com/showthread.php?s=&threadid=27918

I am totally lost here people. Anyone technically inclined with an educated
guess among you???

Chris
1992 Sunny 2.0GTi