1991 Park Ave Engine keeps dying

Last week I went to the gas station filled my PA with gas and proceeded on my long drive home. When I tried to engage cruise control the light kept going on and off. After a couple of minutes the check engine light came on and my car died. I restarted it and a while later it died again. The car kept jumping and had no power. I took it to the mechanic and they said it was a throttle sensor, which they changed. When I picked the car up I started it and it died. This time the engine was idleling high and as i took off there was no power. When I stepped on the brakes it died. Any idea what the problem could be, they have now sent it to a transmission shop where they got a code for an electrical problem.

Just so you all know it was the ECM.......