So I have a 2006 altima that needed a head gasket change. Prior to changing it, I checked compression and all cylinders had great compression. During the fix, everything went smooth but I lost timing. Took the timing chain cover off and set it all back up. Tried to start up and it did not start and there is no compression in any of the cylinders. IS the timing off or is their like a head leak or something like that? The diagram seems easy enough but can anyone describe the steps they took? Also, the cam on the exhaust side broke and was replaced but the numbers etched were different than my stock one. Visually looked the same and was told it was from the same year car but wanted to verify with you guys. Thanks in advance.