I replaced the head gasket on my 4g64+4g63 build and had to install the timing belt again. Got the timing marks on trigger and cams as they should be (I have done this before) and I wanted to check, how near the TDC really is. Found the real TDC with dial gauge and the timing was off? I put the lower cover on and when it was at real TDC, the cover and pulley marks lined fine.

My timing was about 10 crank degrees off (R), so I removed the trigger plate and it had moved about half off the guide pin. The guide pin looked fine, but the groove of the trigger plate was about 1.5 wider than it should be. Somehow it had "eaten" wider groove there.

Over a year ago the crank pulley dropped of and I had to replace the lower timing sprocket because the bolts broke inside the sprocket. Probably the damage of the trigger plate has started those days because of the vibration. At that time, I didn't check the trigger plate and the car has been running fine.

I am now waiting for a new trigger plate. It's good to double check the timing before you start the engine.