I don't know what happened to rigs where you worked. I worked on many 5.7 and 6.2 GMs when they were new. Biggest problem was the plastic dampener coming apart on the governor and that had nothing to do with fuel. That problem was eliminated in model year 1985 in all Fords, Chevys, and GMCs. Besides the fuel was fine in the USA until they started cooking the lube out of it to make ultra low sulfur fuel. Military rigs were and are a whole different situation because they all used A-1 jet fuel or JP8 military fuel with low lube. The US Army was putting Stanadyne "Arctic" fuel kits in many to make them last longer. It was often the low-pressure advance pump-blades that wore out.
Here's a list of military spec pumps on 6.2s. Anything with the "1.2 cSt" at the end has an Arctic kit installed.
DB2829-4355 23500014 1984 HMMWV (Military) C/K DB2829-4471 Note 5
DB2829-4440 23500276 1985 HMMWV (Military) - 1.2 cSt C/K DB2829-4523 Note 2
DB2829-4471 23500398 1985 HMMWV (Military) C/K DB2829-4524 Note 2
DB2829-4520 23500413 1986-87 CUCV (Military), HD D Truck C/K
DB2829-4521 23500414 1986-87 CUCV (Military), HD D Truck - 1.2 cSt C/K
DB2829-4523 23500415 1986-89 HMMWV (Military) - 1.2 cSt C/K
DB2829-4524 23500416 1986-89 HMMWV (Military) C/K
DB2829-4847 10149679 1990 HMMWV (Military) G DB2829-4878 Note 8 exc. (e) & (f)
DB2829-4848 10149634 1990 HMMWV (Military) - 1.2 cSt G DB2829-4879 Note 8 exc. (e) & (f)
DB2829 - 4875 not listed as military but military suplus shows they were purchased for $1800 each.
DB2829-4878 10149633 1990½ HMMWV (Military) G
DB2829-4879 10149634 1990½ HMMWV (Military) - 1.2 cSt G
DB2829-4879 10149634 1990½ HMMWV (Military)
US Army did a study on Stanadyne pump wear in 6.2s and 6.5s and released these results:
Xl. RECOMMENDATIONS
The following recommendations are made as a result of this study:
1. In areas outside arctic applications (i.e., Alaska), continuous use of neat Jet A-1 should be discontinued in Stanadyne pumps.
2. JP-8 or equivalent appears to provide acceptable pump durability.
3. The metallurgy in the arctic components represents a significant improvement and should be used if possible.
4. The results from the present limited study indicate that a BOCLE wear scar diameter of approximately 0.65 mm corresponds to the minimum acceptable fuel lubricity
5. The following areas require further study:
a) The effects of temperature on fuel system wear. For example, until data to the contrary am obtained, continuous use of Jet A-l/DF-A fuel on year-round basis in arctic areas such as Alaska is judged to be acceptable.
b) The effects of sulfur content and fuel composition in general on fuel system wear and its relation to the standard bench wear tests.
c) Scuffing wear and its measurement
d) The effects of fuel lubricity on the durability of other fuel injection systems besides Stanadyne, especially unit injector systems.
Info from:
9. "Accelerated Fuel-Engines Qualification Procedures Methodology Engine Test 210-Hour Wheeled Vehicle Cycle Using the GM 6.2L Diesel Engine Operating on JP-8 Fuel," prepared by U.S. Army Fuels and Lubricants Research Laboratory, Southwest Research institute, San Antonio, TX, October 1985
11 "10,000 Mile JP-8 Fuel Test of 6.2L Diesel Engines in M1028 CUCV Vehicles", prepared by General Motors Corporation Military Vehicles Operations, STS CUCV % PROJECT REQUEST 87-027, Warren, MI, July 1987.
12. Montemayor, A.F. and Owens, E.C., “Comparison of 6.2L Arctic and Standard Fuel Injection Pumps Using JP-8 Fuel," Interim Report BFLRF No.232 (AD A 175597), prepared by Belvoir Fuels and Lubricants Research Facility (SwRI), Southwest Research Institute, San Antonio, TX, October 1986.
20. Lacey, P.I. and Lestz, 8.3.. "Failure Analysis of Fuel injection Pumps From Generator Sets Fueled With Jet A-1," interim Report BFLRF No.268 (AD A234930), prepared by Belvoir Fuels and Lubricants Research Facility (SwRI), Southwest Research Institute, San Antonio, DC, January 1991.
21. Lacey, P.I. and Lestz, S.J., "Wear Analysis of Diesel Engine Fuel injection Pumps From Military Ground Equipment Fueled With Jet A-1," interim Report BFLRF No.272 (AD A239022), prepared by Belvoir Fuels and Lubricants Research Facility (SwRI), Southwest Research Institute, San Antonio, DC, May 1991.
25. Stanadyne Service Bulletin No. 125R1, "Field Conversions for Low Viscosity Fuel Operation," December 1990
52. Kanakia, M.D. and Moses, C.A., "Study of Mechanisms of Fuel Lubricity” Letter Report BFLRF No.250, prepared by Belvoir Fuels and Lubricants Research Facility (SwRI), Southwest Research Institute, San Antonio, DC. August 1989.