1990 3.0 V6 will start and drive for 10 minutes then die! Help please!

My 1990 3.0 v6 will start just fine and run awesome for about 10 minutes then randomly die. Sometimes it will start back up and other times will not. It's throwing codes 12, 14 and 71. There is a black box about 1 inch by 1 inch that connects to the coil/igniter assembly that has one wire broken. The wire looks like it leads into the top of the motor somewhere. It ran just fine for a few months without replacement. Do I have to get a new black box thing or is something else going on with the pickup? Any suggestions/help would be greatly appreciated! Ordered a new coil and igniter.. will be putting them on tomorrow and see if that fixes it.

 

I would suspect one of those codes is the culprit. Not sure on the 14 though?

Check out http://www.troublecodes.net/toyota/

Any chance you can get a decent picture of the black box you speak of?