water injection questions

[Robert Yorke]

George:  I haven't the slightest idea why this would occur in your car;
apparently the ECM in some way adjusted the advance to take advantage of the
higher octane gas being used, then required a re-adjustment period to
compensate for a return to 87 octane gas...  Does your shop manual describe
in any way this kind of ECM operating characteristic?  If this is indeed
what happens with your ECM, it's a hell of a lot more sophisticated than the
C3 ECMs in V-6 Fieros!

At 05:24 PM 7/23/96 -0500, you wrote:
Snipped
>
>How would GM EST react to this situation? On my 89 TPI set up, I noticed
>that after running high octane fuel for a week and then switching to the
>cheap stuff, if I floored the throttle I would hear a few detonations and
>the check engine light would come on. Code 43 EST. After two or three times
>of this, it would start working normally. Does it take the ECM this long to
>adjust.
>
>GMD 
>
>
>
2 "88 GTs, both autos!