You can't adjust the injector pump sprocket on a TD engine - it's fixed on a woodruff key. There is a hole, but it's in the side of the pump body, and you need a special timing setting pin to get the timing dead right. There are two timing marks on the injector pump sprocket - an 'F' mark and a 'pip'. The timing is set on the pip, and the cam in a similar fashion. If you are checking the timing with the radiator still in place, then the cam sprocket appears to be 1/2 tooth out - due to the angle you are looking at it. I use a 6" steel rule to check the position of it. If the radiator is out and you are looking at the timing mark square on and it is 1/2 tooth out, then I would suggest you remove the cam sprocket and check the woodruff key isn't about to shear off. You can fine tune the timing without the setting pin, which involves slackening both ends of each injector pipe, the three nuts that hold the pump to the timing rear case, and the nut/bolt on the support bracket at the rear. The pump can then be rotated - limited by the three slots that the timing rear case studs pass through. The pump should be marked in relation to the rear case before you move it (so that you have a reference point), and then only turned 1mm or less (injector pump timing is very accurate). If you can get the engine running and it blows white smoke out of the exhaust in intermittant puffs, which gets less as the engine warms-up, then the timing is retarted. If the engine knocks (detonates), then the timing is advanced. If the injector pump timing is retarded, then it won't start on the key, but will on a tow when it's cold, but will start on the key once the engine has warmed up. Accelleration will be very slow and there will be a lot of white smoke.
The timing arrangement and belt replacement on a TD/NA engine is covered here (but not using the setting pin).
http://forums.lr4x4.com/index.php?showtopic=7880Les.
