Harness pins not on tight?

[dvd]

I had problems before with the harness causing the car to missfire. This was a year ago on the 240. Then recently i dropped the ca into the 510 and i was messing with one wire(coilpack #4 wire into the ecu harness). But now it doesnt work again. Could it be my safc? I dont know, i wiggled the wires and now it doesnt help. Any suggestions to make sure the connection is tight?