I bought a new memcal for my ecm, because I was getting an error code that said my old one was bad.

Well I am currently running a super_aujp_v2 chip in my car now.

I decided to install the new memcal with a stock aujp chip to get a good baseline with the new memcal. Well when I tried to fire it up it would just cough and sputter but it wouldn't catch and fire.

I took the stock aujp chip out and put back in my super_aujp chip and it fired up. (although still a little rough).

What do you think my problem was?

 

VATS?

 

Could be that you had changed the injector constant of 22 and/or the base timing from 6 BTDC. Those are the stock settings.
You would have the VATS enabled with the stock chip like AlxexJH said too. (I'd think the VATS was the main reason)
If your old one was throwing code 51 you may have just had the checksum wrong or something like that.
Make sure the memcal you bought is for a V8 application if it was not a new AUJP complete. (I'm guessing you have an adapter on there and put in a burned "stock" bin)

 

Yeah I tried a burned "stock" AUJP in there at first.

I was pretty sure I disabled VATS on it, but I guess I can doublecheck....