Ok thanks! IIRC the timing was at 3-3.5 when he tried to do the timeset and when he did the learn it jumped to 8-9 but once off it was back to 3-3.5. It sounds like it may be good. We'll do the battery and see what happens.iirc the time set feature in GMTD or on a tech2 is just to allow you to see where the IP is at (if it needs to be adjusted before doing the TDCO) once you have the IP in or near the 3 - 3.5 deg area, then you off to set the TDCO. the TDCO is the only setting that gets retained in the PCM and should be all you have to do to set the timing.
when you reconnect the batteries and connect to the PCM, if the TDCO number is the same as what you got in your last post without functioning the time set or learn buttons (just reading what's on the screen) your good to go, no need to do any further changes, unless of course you want it closer to spec. imo I would leave it at -1.78 and call it a day. getting it any closer to spec (-0.7~) you will be there all day and then some bumping the IP back n fourth fractions of a hair's movements and re-running the learn procedure!