If you get it from ************** they send directions. But IIRC when I did mine, you get it in there till you feel a little resistance and start the car. If it idles (even rough) get it up to operating temp and start bumping it in until the engine smooths out. If I were to feel significant resistance I'd stop turning it and start looking at other causes for the problem. From what I understand, it's kind of like that ALDA adjustment screw--you really don't want the things inside the IP attached to it to break.