How do I check the operating status of the 82 Computer?

From the information I have Code 12 is normal operation, if your wires are shorting then that would be a big issue, make sure the plug wires are for HEI, not sure hoping some CFI guys will chime in but once the computer is reset it needs to run for a will to relearn the system. from the discription it sound like you hav some bad wires.

Code 12 is simply a code that lets you know the ECM is in diagnostic mode...it means nothing else.
I agree with the plug wires causing the problem, too. Do the usual tune-up stuff first, since you know there is a problem there. The ECMs don't fail all that often, but they usually create more problems than you are having.

You can get the wiring diagrams Here....er...well...you COULD. Seems Ben's server is down at this time...
I can e-mail you the '82 diagram if ya want....

Did the problem just appear suddenly or was anything changed prior to the problem appearing?  My factory service manual shows "Code 12 indicats that the distributor spark-tuning reference pulses, which are generated by the pickup coil, are not being received by the ECM".  Double check everything at the distributor including the coil.  Not sure if the ignition module in the base of the HEI distributor could cause this problem or not but they are very prone to fail and can cause erratic engine or a no start / no run condition.  The forum does not have an official photo library that Im aware of  but if you will tell me what you need if its for an 82 Ill see if I have anything that will help.
Crossfire19822011-06-05 06:49:49

Having no Cat is not a problem, the O2 sensor is before the cat and works the same with or without the cat. I would start with a tune up with new wires, new coil & ign. module first. DaveM2011-06-04 17:55:47

Thanks for the fast response - I'll keep checking in on the link you sent to catch it when it is back up.  And yes! I would really appreciate any diagrams you could share.

It kinda came on suddenly - At first I thought it was weather temperature related (really had me puzzled) - it seemed as though the computer was confused and couldn't make up its mind trying to figure out how it was deciding to run. Then after about 5 mins of this foolishness it would settle down and run good.  once the weather got warmer things were good. Then I had a chance to wash the engine with my handy dandy electric pressure washers. Then it began to run rough. Then quickly running like it is now - seeming like it is running on 6 cylinders. It always starts easily - nut runs terrible, weak, and sneezing when I put a little too much toe into the throttle (way less then normal).  

Cleaning an engine with a pressure washer is not a good idea when you have a lot of electronic components involved. It's possible that some of the electronics were damaged, and that caused the problem to get worse. The TPS(Throttle position sensor), MAP(Manifold air pressure) sensor, and others are very sensitive to moisture. Unless you carefully covered all of the electrics when pressure washing, you may have more than just tune-up related problems. I would definitely start with the tune-up first, for sure...it sounds like it needs it anyway.
Wiring diagram will be on it's merry widdle way shortly.

I had the air cleaner chromed after looking for years for to find one.  I kept looking on ebay until I found one at a decent price and bought it, took it to a local chrome shop and they took care of the chrome work.   You have a PM
Crossfire19822011-06-05 06:52:07

Wow! 20 mpg?  Really?  What else have you done besides the Cat removal?  I have removed and cleaned the contacts on my 82 computer.  Not a bad idea.  I use Caig D5 contact cleaner.  The O2 sensor regularly flags on my 82.  It controls the enleanment and enrichen functions while in closed loop mode.  When it flags the system goes into enrichen and the limp home mode.  That is my understanding of it's function.

Keith