injector issue?

[Joehop]

I have a 931a2 with the 8.3, It suddenly started knocking pretty bad the last time it was started. It ran fine the previous start. The knocking seems to be coming from the rear top of the motor but somewhat hard to tell. I plan to check it with a infrared thermometer to see which cylinder may not be firing. Any suggestions? bad injector possibly? exhaust smoke is white
thanks

 

[Suprman]

Change the fuel filters and look for air getting in somewhere first. Could be alot of things.