LDT 465 Injector Advice

[Welder1]

I will be replacing my injectors on my M35A2 truck in the near future. I have several sets available I can use. I have the older style shim adjustable 2 hole units AKF 130S 6614A and the later AKN 130SM 6844 B2 ones. The AKF ones are brand new Bosch units and they pop test at 2750 PSI. The AKN units are AMBAC Italy units that use the 770138 tips. These are rebuilt ones set to pop at 3600 PSI. So what is the opinion on which to use? Both are 2 hole units and display similar spray patterns. I don't fully understand the difference and looking for more education regarding them. Let me know your thoughts.



Eddie Cannon

 

[cattlerepairman]

My diesel injection guy is currently r&r my injectors. He mentioned that, within reason, the exact pop-off pressure is less important than the injectors opening at the same pressure (balance). Higher pop off pressure means better spray pattern and as more precise "injection window" for injection timing. Your sets are set too low and too high. Spec as per TM 9-2815-210-34-2-2 is 3050 to 3150 for new nozzles and at least 2800 for used.

The IP probably has enough grunt to run the nozzles at 3600 psi, but I do not know if it would noticeably increase wear and tear on the hydraulic head and plunger. I would re-adjust the screw-adjustable ones to spec and use those. I would love to say "If in doubt, trust the numbers from the guys that built the darn thing!" But that is the same guys that tell you to torque the injector hold-downs to certain destruction....that torque value in the TM is mega-too-high....