Volvo S40 - 2001 1.8i Engine stalls since battery removed and replaced Is this common and do you need to reset anything?

sometimes after replacing the battery you have to adjust the Johnson rod i have the same vehicle when i replaced the battery i just pulled the rod a little and since i have had no problems

Is there another name for a Johnson rod as my car is doing the same thing. My dad has looked at it he has been a mechanic for 40 years and has never heared of a Johnson rod. The problem is driving him mad as he can't fix it for us.