The diesel fuel injectors in modern Tier III and especially Tier IV engines are incredibly fussy about fuel quality. They are precision devices, to the point where if you disassemble one and hold the piston in your hand but leave the injector body at room temperature, the piston will expand from the heat of your hand so that it won’t go back into the bore of the injector. Even the teeniest amounts of contamination can cause problems under such precise clearances.
That’s probably why I noticed so many rough running engines over the winter. They didn’t have an actual “miss,” but didn’t run as smooth at low throttle as I’d like. If they were opened up to full throttle, the roughness wasn’t noticeable, but if connected to an engine analyzer there were usually inconsistencies that were corrected only by replacing one or more injectors. Which can cost thousands of dollars.
According engine manufacturers, the best way to prevent gummed up or malfunctioning diesel fuel injectors is to use some sort of fuel conditioner in the fuel. I know--it’s really annoying to have to add stuff to every tank of fuel. It’s not because your fuel supplier is supplying poor quality fuel. It’s just that the newer engines need all the help they can get to keep injectors from getting messed up.
My advice is to talk with an engine mechanic you trust and get his suggestions on what sort of fuel treatment to add. All the mainline engine manufacturers offer fuel treatments. There are plenty of aftermarket products as well. All of them add to the cost of simply filling the fuel tank on your tractors, but they have the potential to save thousands of dollars in repairs to fuel injection systems.
