Did someone pull the pump off and not pump time it? Most injection pumps have a plug you "push" into the pump to lock the pump on TDC. Cummins also have that on the back of the cover or on the flywheel to lock the engine on TDC. Regardless number one cylinder will have to be on TDC to install the pump and on the gear there is prob a dot to revel the timing marks for the front timing gears. But if you don't know which stroke the pump is firing on then..... Could get interesting.
