Finding Top Dead Center

a friend of mine needs help finding top dead center on his '85 Diesel Jetta. he doesnt feel like taking the engine apart to figure it out and theres no timing marks on the cam sprocket or injection pump. actually i just talked to him and he needs to know if theres a way to find top dead center on the cam? without timing marks? any help would be great. thanx.

No, there are no marks on the cam sprocket as it can be rotated on the camshaft if you loosen the bolt. The TDC point for the cam is on the other end. There is a slot cut into the end that, when you insert a special tool ito it, will lock the cam to the cylinder head. If you can find a piece of metal the proper thickness to fit into the slot you can use it to lock the cam. The injection pump has a smaller hole in the sprocket that a special pin will fit through & go into another hole in the housing, thus locking it to TDC. If he's trying to reset the belt timing it is a nearly impossible difficult process with out the correct tools & a manual.

Quick and slopy TDC trick

Look at the cam over the first cylinder, when the cam lobs for it are both facing down and they are both the same distance up from the valve, you have TDC. This is not a sure fire perfect method, but I did a cylinder head job on a 1978 BMW 518, and this is the method I used and she fired right up after it was done. If this works, your friend is a true backyard mechanic.