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    This is a short add-on to my earlier post - can you stop the monster. It pursues, basically, two purposes - one - to present yet another amusing example of how unstoppable the mechanically injected diesel engines can be, and two - to provide a proof to the universal fact that in absolutely any situation, despite all training, planning and preparation, something at some point will go wrong!

    About a month ago I got involved in restoration of an outdated Toro 500 - a heavy underground front loader, powered by a true engineering miracle - a V-twelve Deutz diesel. These air cooled engines, equipped with mechanically governed injection system  (and I am referring to all versions, not only to the V-twelve), have earned the fame of being bulletproof survival experts, capable of putting out countless work hours under all sorts of abuses and environmental ill-treatments. I was told at the mine that due to the newest environmental restrictions they weren't allowed to buy such machines any more, but were still allowed to run the already existing ones. This particular loader had been stationary for about two years before a decision was made to "resurrect it" as an auxiliary piece of equipment. Since for the last year the machine had served as a spare parts warehouse for its alike brothers, it was "partially missing" when the works started, and after the reassembly the hydraulic brakes wouldn't work - which was the main reason I was called to assist.

   The malfunction turned out to be bad connections. Luckily, the hydraulic schematics was there, and the the problem was quickly solved. While making the necessary adjustments and verifying the rest of the hydraulic system, I had to turn the engine on and off several times. Since I had already had my share of, let's say, peculiar experiences with unstoppable diesels, one of the first things I checked was the engine shut down system, which was working flawlessly, and was activated by a small spring pre-loaded hydraulic cylinder. To stop the engine a valve injected oil into the cylinder, and the cylinder would pull or push on something, and the engine would stop. I am not sure whether it was a decompressor or a fuel valve, but it doesn't matter really.

   Everything was working fine, the engine was starting and stopping whenever required, and my job was almost finished. As I was talking to the shop mechanic, I pointed out a pilot line oil filter, which apparently had never been replaced as nobody knew it was there. The all helping fellow immediately took out the filter element and rushed to the warehouse to get a replacement. The filter cap, naturally, remained unscrewed... Very pleased with myself (the job had gone incredibly well...) I deiced to make but one last pressure check, and "the funny part began..."

   Just like I'd been doing it for the last couple of hours, I installed a pressure gauge, went to the cabin, and turned the ignition key... By the moment the key had gone around half of the travel a lightning fast thought flashed thorough my mind - an open filter in the pilot line means no pilot pressure, you moron!!! How the hell are you going to stop the engine?!! - by that time my brain gave the fingers a command to stop turning the key, but it was already too late  - the tenth of a second the ignition contacts touched each other was enough for the stupid but very well adjusted diesel engine to start turning... By instinct I pushed the stop button (what a fool!) already knowing that there would be no pilot pressure to operate the stopping mechanism (which, by the way, was well hidden in the middle of the engine). I climbed the three meter high machine in under a second, and saw exactly what I was expecting to see - the engine going pa-pa-pa-pa, and the stream of hydraulic oil coming out of the dismounted pressure filter and poring all over the loader and onto the shop floor...

   The hours were late, and since the shop mechanic ran to the warehouse I was alone with the mindless critter, which was poring gallons of hydraulic oil on the floor. Calling for help was not an option since I couldn't possibly outscream the twelve jugs, so I had to find a way to stop it, and stop it fast (but not for good...) I looked around me, and saw a piece of rubber band on the floor, which seemed to be large enough to cover the intake, so I went for it and spread the band directly over the huge air inlet - I could swear it was air tight, but the f#cking engine wouldn't stop!!! I was looking at it and wasn't believing my eyes! How in hell was it possible?!!! The diesel was clearly choking, spitting out clouds of black and white smoke from the exhaust, but it was not stopping!!! In another desperate attempt I managed to twist the fuel hose in my hand, and after half a minute of doing ta-pum-pum-ta-pum-chaka-chaka the starved bustard finally seized kicking. When I cooled down and descended the loader, doing all my best to avoid landing in the oil pool on the floor, I finally looked at the engine with a "seeing" eye and noticed that the V-twelve had two air intakes - one for each six cylinders - so to smother it I had to close both of the inlets... which I didn't.

    To conclude this - once again, mechanically injected diesel engines can be a pickle to stop once they've started turning, so before putting one in service, make sure the shut down system works and that you have studied other stopping options. Oh yes, one more thing - in case you consider smothering an engine, don' t forget that it can have more than one air intake!!!