Just started researching FDC info since a M109A3 purchase has a big yellow "Diesel only" sticker on the fuel filter housing.Just wanted to clear a few things up from your statement Eagle.
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Also the military actually bypassed the FDC as a MWO. This was due to the fact that these engines were designed back during the Vietnam war. The reason for the multifuel was to power a truck with an engine that could make use of any fuel available due to supply issues. The FDC "later in life" began to fail with it's seals. This lead to fuel contaminating the engine crankcase. (Thinning the engine oil leading to damage) Since supply issues had been overcome since the wars in which the multifuel was designed, the military opted to simply bypass the FDC and run strictly JP8 or Diesel.
Sounds like I should leave it "as-is" based on this information. Curious why my much newer 1987 M35A2C didn't come with the FDC bypassed/yellow sticker based on this information?