Problems with the KA24DE

[GMoney22]

I was having problems with the KA24DE motor that involved it to begin to putt once it reached normal temperature. It dropped down to 500 RPM and had no power, and it would at that point completely shut down. I just swapped the motor and transmission, but it wasn't an SR20 swap. I got the same motor, but swapped it to a standard. I've had the car back for one week, and it seemed to be operating fine. However, just the other day, I guess the temperature affected the motor, because the same problem started happening again. I replaced the Mass Air Flow Sensor, and that did not solve the problem still. It is running fine now, but once it gets hot it starts acting up again. Could this be electrical? Does anyone have any idea what the problem might be?