Engine/Transmission (1994 - 1998) timing procedure for rebuilt injector pump at tdc

[SGastelu]

Im trying to get the engine at tdc. Turning the engine counter clockwise by hand and trying to find the hole in the cam gear where the dowel goes. Does the hole go completly thru? Im watching the exhaust valve on number one just start to open but cant find tdc. It seems very hard to look with a mirror and flashight when trying to work alone. Any advice?

 

[JGK]

One of the easiest and most accurate ways (though a bit time consuming) to find TDC is using the exhaust valve on #1. However, you have to be able to rotate the engine both ways. And its best to have a someone with their hand on the rocker arm for the valve.



Rotate the engine in the normal direction watching the valves on #1 (cover off, of course). Watch for when the intake valve has closed after allowing the next charge of air in (piston should be at bottom of stroke. Loosen the exhaust valve lash retainer nut about 6 or so turns and screw down the exhaust valve 5 turns after it snugs up against the valve stem. Now rotate the engine until the piston stops up against the valve. This is where another hand on the rocker helps as they will feel it make contact. You don't need to really worry about bending the valve. You'd have to crank pretty hard to do that. But someone's hand on the valve helps with peace of mind.



Make a pointer out of a piece of wire and fasten it under one of the oil pan bolts down below. Or you can take extra time and put it under one nut of the crank sender at the top of the damper. That way you can see it from above. Put a long piece of masking tape on the perimeter of the damper and mark it where the pointer is as the piston rests up against the exhaust valve. Whether you do this with the pointer on top or down below (pointer under a pan bolt) doesn't really matter.



Now rotate the engine backward until the piston comes up against the exhaust valve again. Mark the tape at the pointer. Exactly half way in between is TDC at your pointer. (Using this method and screwing down the valve adjuster 5 turns always results in two marks about 95 mm apart on the tape for me. ) Back the piston off from the valve, reset the valve lash to spec, find the mid point on the tape and scribe the damper at that point. Remove the tape. You now have a permanent, virtually dead-on TDC mark. Rotate the engine forward, watching the valve action. When your mark lines up with your pointer, you should easily be within a degree of TDC if you did it right. It takes a little while, but worth it.



There are other ways that involve using a dial gauge on the valve and compressing the spring, or some other. They work too. In any case, these methods are far more accurate than relying on the timing pin.



-Jay