So, you made a basemap in crome and, with crome, it was fine one day and rich the next?
Its definitely not a bad chip: if you had a bad chip, you would get a solid CEL and the car wouldn't rev over 3100rpms.
Uberdata does not allow you access to any intake air temp or coolant temp correction tables, so you're a/f can definitely change from day to day/season to season..... but if its extremely drastic.... did you change anything on your setup besides the map since then? I.E., fuel pressure, fuel pump, any wiring, etc.?
Here's a thought: does the voltage of your car's electrical system flutuate? Just recently I tuned a car that had an issue with the OBD2->OBD1 conversion which caused the alternator signal wire to be improperly interepreted. The result was an erratic voltage on the entire system and unpredictable times (which can easily cause your problem). I see your car is a 1996 and you're running uberdata (obd1)... what conversion harness are you using? Check this out:
I guess OBD2 cars have a different alternator wiring setup as OBD1 cars. So when you convert to OBD1, there is a wire that is not used that goes to the alternator. This wire actually changes the voltage that the alternator sees and causes the regulator to shut on and off. This wire is called ALT-C, located at A16 on the OBD1 side of the harness. If you cut/remove this wire from the harness, the car charges like normal again.
Try that out: check to see if you have a pin at a16, and cut/remove it if you do. See what happens after that
Also, you're going to max those 310's out very quick. As long as you can still idle, there's no downside to running a larger injector... it leaves you more room for future upgrades/higher boost/etc. If you want a direct replacement, get saturated injectors. If you end up runnign peak-and-hold injectors, you'll have to wire in a resistor box (like $5 at a junkyard and its not hard to install)