At 08:27 PM 12/30/2010, Old Volks Home wrote:
>Keep in mind that the ECU on the 1.9 is installed in the rear left
>side of the engine compartment, subject to lotsa vibration, dust, dirt
>and engine room heat.  2.1 ECUs are usually mounted in the passenger
>compartment underneath the rear seat away from the noise, vibration,
>dirt, dust and heat.  Might make a difference (good or bad-who
>knows?).

Difference is that the 1.9l bracket is somewhat compliant in the
fore-and-aft direction and possibly up and down as well, thus
allowing the ECU to vibrate with possibly lower G-loadings compared
to the 2.1l which is quite firmly attached to a stiff bracket and
panel.  On the 1.9l T-A I just opened (and on the Bosch I had open
long ago) there were solder problems with heavy things, things with
leverage, things with significant thermal cycling and so on; but on
the 2.1l ones I've been seeing, for example, the T-A ones have
trouble with the light flattened-ribbon connectors connecting the two
boards, which have very little mass, no thermal cycling, no
unrelieved mechanical stress - that's fairly ridiculous and to me
points to a fast-rise-time vibration that can disturb these very
light components; and many other components have problems that I
likewise wouldn't expect because they're lightweight and don't extend
far off the board, don't get hot etc.

Yours,
David