If the injection shop is going to charge you substantial coin. You may be able to mark the number five pump element adjustment and try manipulating it instead.. The knock should go away.If not just place the adjustment back on the original mark and take the pump in.

Later when more time is available you can use the milli volt method to make sure the cylinder is running at the same temperatue as the others. This is not a perfect solution but no harm should be done. You do not have the time to do a proper set up for the milli volt method right now prior to the adjustment.

The number five element sounds advanced to me. There is also a chance the number five elements delivery valve seal has deteriorated with the pump sitting around for years. I cannot visulaise the calibration adjustment going off what it was set at really with the pump not in service. My suspicion is they might have calibrated the injection pump while accidently using a bad injector the last time.

I was kind of suprised the older mechanics did not quickly check with an injector substitution and attempted the manual correction themselves. Marking the adjustment well means that if it later proved to be a delivery seal issue you could also put the pumps element back to the same position. I do not know where the element adjustment is for the 603 type injection pumps. At some point they went internal but are still managable.