1990 244DL

Briefly: I previously posted that I was getting a 232 and 113 code. I would disconnect the battery and then the car would run fine for a few hundred miles and then the check engine light would come back on. Then, more recently, the idle would drop and rise without cause, and was loping at all times. I found this weekend that one of the spark plug wires was badly corroded at the dist. cap.( they were only 20,000 miles old) I replaced all the wires and the cap and rotor. The car ran superb! It idled rock steady at 750 RPM and was quiet, quiet, quiet.

Then it happened again. After driving 200 miles - the idle became slightly rougher and the check engine light came on again; the same codes. So again, I disconnected the battery, and upon reconnection it ran perfect again. What's going on here? I read something in the FAQ about a bad ECU possibly being the cause for this. Has anyone else experienced this type of trouble. What I find so perplexing is that the car will run perfect for a few hundred miles and then you need to unplug and replug the battery effectively resetting the ECU, for it to work fine. It seems to indicate to me that, in fact, there isn't anything really wrong with any one part, otherwise it would reveal itself right away instead of after 200 or so miles. Thanks for any insight.