If your lifter is sticking, there are a few things you can do to try and free it up. First, make sure that the lifter is properly lubricated. You can do this by adding some oil to the lifter or by using a lubricant specifically designed for lifters. If the lifter is still sticking, you may need to disassemble it and clean it thoroughly. Once the lifter is clean, reassemble it and see if it is still sticking. If so, you may need to replace the lifter.