ABA timing issue

[Tifun]

Ok, here's the deal, for some reason the car keeps jumping timing. I've had the head off and everything looks fine, had it checked at a shop as well, no problems there. Also the bottom end is fine. I've lined the marks up more times then I can count and started the car. It idles fine for a few minutes then bam, it runs like poop and then when I shut the car off and look at the marks they are no longer in alignment...

What am I doing wrong??? I've pulled it all back off, minus the head. Basically the car is sitting without the timing belt on it until I figure out what I am doing wrong. This is getting very aggravating to say the least. I obviously am missing something critical here.
-Keith

[Tifun]

Ok, I did tons of research and hope that what my problem is, is that the key-way on the crank gear sheared off. Not a very common problem, but with everything I described it fits very well into what is could very well be. Lucky for me I have the old bottom end. So I will just swap the gears and be done with it. If that's not the case, then I have no freaking clue as to what to do. Hopefully I can have the car on the road today.

[A4Jon]

How's your cam-chain tensioner looking? Had that happen to my first motor... bad juju.

[Tifun]

How's your cam-chain tensioner looking? Had that happen to my first motor... bad juju.

it's a belt. Also it has a new manual one. I think it might be my crank gear. I think the keyway has sheared off, thats what my research has shown so far, just need to get out in the cold to do it now.

[A4Jon]

How's your cam-chain tensioner looking? Had that happen to my first motor... bad juju.

it's a belt. Also it has a new manual one. I think it might be my crank gear. I think the keyway has sheared off, thats what my research has shown so far, just need to get out in the cold to do it now.

No, I'm talking about the Cam-Chain tensioner. When you lift the valve cover off to expose the cams, at the aft end there is a chain that links the intake and exhaust cams together. This chain is kept under tension by oil pressure transmitted to the riser that sits between the cams and under the chain. If the riser (cam-chain tensioner) is not keeping the chain at the proper tension it can jump back and forth.

[Tifun]

How's your cam-chain tensioner looking? Had that happen to my first motor... bad juju.

it's a belt. Also it has a new manual one. I think it might be my crank gear. I think the keyway has sheared off, thats what my research has shown so far, just need to get out in the cold to do it now.

No, I'm talking about the Cam-Chain tensioner. When you lift the valve cover off to expose the cams, at the aft end there is a chain that links the intake and exhaust cams together. This chain is kept under tension by oil pressure transmitted to the riser that sits between the cams and under the chain. If the riser (cam-chain tensioner) is not keeping the chain at the proper tension it can jump back and forth.

It's an ABA, it doesn't have one