Did you remove the two bolts that go forward into the timing cover? They have 1/2" hex heads, and I believe there is a locking tab that must be bent away from the bolt heads to get a wrench onto the bolts. Sometimes it's necessary to pry or tap on the cap, as there is a gasket between the cap and the timing cover that can stick them together if sealer was used when the cover was installed.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!