So I needed too move my tractor off the critter pad after our last flood (it was never under water whatsoever) and parked it on Monday. I go to start it yesterday to move our box scraper to a different place. When I try to crank it it clunks, not clicks like a dead battery. I try again and diesel fuel comes trickling out of the valve cover vent hose. I thought it strange but moved on to other projects. Today I go to start it, same thing just no venting fuel. Being worried about hydro lock I began opening it up. First thing is the air intake and the manifold is full to the brim with diesel... oil dipstick has fuel soaked oil halfway up it. Turns out about 5-8 gallons of diesel ended up everywhere in the engine. All 4 cylinders are completely full too. My question: *** went wrong? What would cause half the fuel tank to empty through the injectors (I assume) and into the engine while it's off and not moving? I believe I have a microbial issue that has been long running and only discovered within the last month. The one injector I could get out looked pretty gnarly and the fuel is cloudy black instead of bright pink and clear like our dyed diesel is. Could that do it?
The little 4600 compact tractor? More likely the fuel transfer pump or one or more plunger pumps is leaking into the injection pump, which runs with engine oil in the basement and drains back into the block, I think into the front cover. i suppose it could be a bad injector but I would say the odds are against it.
I say lift pump too.. IF the lift pump went bad, gravity will drain the tank directly into the injection pump.. The inj. pump will fill and spill into the engine oil.. Its an easy check.. just remove the lift pump and pressurize the "in" pipe while plugging the "out" pipe and check for air at the plunger..