Compression tester result question/engine compression ?

If your cam timing is off then the valves aren't opening and closing at the proper times to trap air and fuel in the cylinders and compress them.I agree with you that the Haynes manuals are vague.That's why I don't like them.Had that happen with an old pickup once.There was a locking washer that had pins on it.One pin went into the end of the camshaft.The other pin went into the timing belt pulley.After much frustration and tearing the motor back apart,I figured out that the washer could be installed in more than one position and it totally changed the timing marks.Changed it around and retimed the engine and it fired right up.