I really have no idea exactly what was wrong with the injectors. I suspect that they were leaking when they were hot as I had the issue only when the car was hot. I tried testing them on a bench both cold and while heating them with a heatgun, I just could not get them to show any sign of problem infront of me, yet after I changed them, the problem disappeared and the problem started after I had them cleaned ultrasonically. Your problem may be different, coolant temp sensor maybe?