Anyone know if the crank sensor trigger is supposed to come off of the back of the balancer? And if it does where does the mark on the back of it line up? I took the balancer off to change the timing belt and it just fell off i lined it up with the key straight up and it just don't run like it should. Thanks for the help

 

I think when key is not in. The hole should be about at a 45 or less degree angle. The rest I don't know. New here. Very new to doing work on my vehicles. Love the learning. I hope I have helped a little.

 

I've changed several timing belts and that trigger never came off so i never paid any attention to where the marks lined up

 

Is this video showing your issue? Not positive because you mentioned position.

 

On a 2.5l the tone wheel, looks like a gear, is press fitted onto the back of the balancer, so shouldn't come off but have seen that before.

You should replace balancer, either new or from a wrecking yard
Reason why is that the CKP(crank position) sensor is the Big Kahuna of sensors, your engine will run with any other sensor unhooked or failed, except the CKP sensor
And its timing sets spark and fuel injection timing.
Cam position sensor(CPS) just fines tunes CKP signal.

Even if you got a new balancer and then used it to line up the old one, then returned the new one for a refund, you still have a very good chance it will loosen up again, and strand you.
It also needs to be exactly in the right position, within 1deg, and as you have found out "close doesn't count" with CKP sensor timing

Found this image of balancer: https://www.carid.com/ic/dorman/products/594-418_6.jpg

Looks like the "missing tooth" is about 10deg off of woodruff keyway

Good images here as well: http://www.ebay.com/itm/Harmonic-Bal...-/301830520891