Recently swapped from 165 to 730. Had everything working with the stock chip in a soldered on socket. Went to make a chip with different inj constant and fan temps. Got all sorts of error codes, tried stock chip again, same thing. Figured a poor connection somewhere.

Currently fixed the problem by buying a brand new prom from GM and slapping it in.

I tested the socket for contiunity (sp?) and checked out but still getting misc. error codes with stock chip or custom. Is there anyway the ESC module on top of the memcal chips could fail?

The car will run with the "bad" prom, but I think it's in limp mode as there is no change between having the chip in place or not.

I don't want to mess with the GM "untouched" prom I current have, but would rather not spend more $$ for another new GM prom?

I also checked the memcal legs and ~ 3 of them seem to be connected in some way, as one pin gives little resistance (normal) and 2 adjacent pins give something like ~20000 ohms.

 

Two words.
Moates Adapter.

http://moates.net/gmecm/hworder.html

You never risk ruining a memcal when you use these, and 100% reliable, hard to beat that combination.

And you directly answer your guestion, yes, I've seen some memcals, just go bad for no reason, what went bad, I don't know. I don't recall having one used with an Moates Adapter die.