For those of you following my search for an ECM, I finally managed to secure a unit out of a 1986 Corvette. ECM is number 1227165, with PROM "BUA". I installed the unit, and the engine sounds much healthier while stationary, and does not seem excessively rich as it did before, though it seems to have a great deal of trouble when under load. It bogs down severely and hacks and pops during acceleration. The "Service Engine Soon" light, which worked perfectly with the last ECM, flickers briefly whenever the ignition is first turned on, and will flicker or illuminate occasionally while the engine is running. Field service mode does not work, and the light only turns on for a second or flickers a couple of times when I enter diagnostic mode. There is no code 12 or anything. Does this sound like a bad ECM? Please help me figure out what the heck this is. I would be especially interested in hearing from those of you who have had to replace ECMs. Thanks.

 

I have found that when I have my computer connected onto my ALDL, but not Diacom running, I will get a flicker on the SES light too. There are no trouble codes or anything wrong. It is just the ecm letting you know that something is connected to the ALDL; in my case the laptop doesn't even have to be on to cause this...just connected.

I should add, that IF I have the computer running and Diacom ready to link, this does not occur, nor does it occur if no computer is connected. Only a computer without Diacom operating.

 

The BUA is prehistoric.
Really an old calibration. Matter of fact I think it was the first none C3 prom.
In other words, if I were you I'd drop by the local chevy store and get the latest 89 memcal, and start with that. Need to unplug the 9th injector and vats disable. But, it's the latest (best) chip for you to start with.

How about swtiching the memcals youhave and see what shakes