If you're looking to relearn your crankshaft position, there are a few things you'll need to do. First, identify the Top Dead Center (TDC) of the engine. This is where the piston is at its highest point in the cylinder. Once you've found TDC, you'll need to find the crank's alignment mark. This will be different for every engine, so it's important to consult your owners manual or a reliable source before proceeding.
Once you've found the TDC and crank alignment marks, you can begin cranking the engine over slowly until the piston reaches TDC again. At this point, both valves should be closed on that cylinder. If they're not, then you haven't correctly identified TDC. When both valves are closed at TDC, that means the timing belt or chain is in correct position on that cylinder and you can move on to the next one.
Repeat this process until all cylinders have been checked and double check your work by starting up the engine and listening for any strange sounds coming fromthe cylinders. If everything sounds good, then congratulations-you've just successfully relearned your crankshaft position!