I was using my Komatsu D31A-17 dozer (approx 1984) to fill in old pond. Engine was running strong for the first hour. It then started to lose power as if lacking fuel (no black, white, or blue smoke). Checked fuel level and it was approx 1/8 full. Added enough fuel to bring it to 1/4 full. Engine returned to normal operation. Another hour into job, same conditions occurred, engine started to miss and lack power. Removed air cleaner but no change. The engine continued to loss power (run slower) until the engine stopped. Approx one week ago I replaced fuel filter as regular maintenance. Some rust was evident inside filter. Any possible solutions? This engine has no computer controls. No fuel leaks are evident. Injection pump is inline Nippendensa.
If it had rust in the filter its got rust in the tank. Which can plug a filter in a matter of minutes. Try filling the tank entirely also. Top it off after every use and it'll keep moisture out. You'll have to pull the tank and get it lined if the rust is to bad.
Yep sounds like plugged fuel filter, fill it with fuel and let it sit overnight, put new filter on in morning and you should get through the day till the job done, when you run it so low then dump fuel in it is stirring up all the rust, O2Dmax hit the nail on the head, I believe
Shut the fuel off back at the tank, then remove the banjo bolt that connects the fuel supply hose to the lift pump. There's a tiny plastic strainer inside that banjo bolt. I've seen that cheesy little strainer shut many machines down.