hey guys. i just picked up a 873 turbo bobcat, and having problems with it. i was told it had a bad turbo when i bought it. i pulled the intake line off the compressor side, and it had horrible shaftplay. i ordered one from norther and put it on. however, this did not help my horrible smoking problem. it smells like straight ddiesel fuel. and if i run the machine for more than 5 minutes, it will start to throw flames out the muffler. and when shut off, it looks as though the intake is getting really hot, as it smokes right off if it i have read that it could be one of several problems. fuel.... i started it, and while running, i cracked each of the injector lines.. each time i loosened one, the machine wold start running bad and missing. this leads me to believe it is getting fuel to each cylinder. i then took the intake pipe off at the compressor and fired up. still smokes. this leads me to know it does not have a air restriction. did i mention that other than it throwing billows of black smoke, it runs flawlessly, meaning it has such a smooth run all rpms. i then pulled the top oil cooler off by removing the clip pins, and seen that the lower cooler was clogged with horrible debris. cleaned it all out to no avail. i would appreciate any and all help i can get with this machine. i am stumped. i do not know the hours, as the only time the bos screnn lights up is at nighttime, but still cannot read anything on it.
I have repaired and experienced fire breathing dragons with similar issues as you describe. In most cases it has been a fuel restriction. One machine had been fueled up the previous day from a remote nurse tank that was contaminated with rust and water. I replaced all fuel filters and it ran perfectly. It was blowing fire, running hot etc. Glowing red exhaust manifolds tells me that the engine is running lean (restricted fuel delivery). One machine had a piece of foam rubber in the fuel tank. Every once in awhile the foam would plug the fuel tube in the tank. It would miss, backfire and run hot. The operator would shut the machine off and the rubber would dislodge from the tube. Start it up and run fine for awhile until the rubber found the tube again. Another machine had a rag in the fuel tank. Same issues as previous only the rag would not dislodge and the issues were continuios. Check your filters-tank and fuel system with a fine tooth comb. It can't hurt and can be very cost effective versus replacing parts. Hope this helps. Z
so, even with the putrid smell of raw diesel it is omitting into the air, it would still be running lean? i thought it was running way too rich.? appreciate the ideas
There are certainly more qualified people on this machine than me that may also respond to your issue. If it was my machine I would definetly make sure there are no restrictions in the fuel system first. Black smoke = incomplete combustion. Causes typically from restricted air flow but you have checked that. Not sure the style of injector nozzle you have but another cause of black smoke can be an injector or two cracking early, basically leaking under low pressure. Another cause of incomplete combustion. Also at an idle or no load condition you may not totally notice an rpm issue but under load should notice engine missing. This would also give you the issue of raw, unburnt fuel in the exhaust system. Broken compression rings can give you black smoke and raw unburnt fuel issues. Do you notice excessive blowby with engine running and oil filler cap off? How old is the fuel in the tank? Bad fuel or old fuel can give you issues. Unstable fuel cetane levels do not produce optimum combustion times/events. A few things to consider but best to start with the one that is most possible, eliminate it and go to the next.
i took the line off that tees into the top of the intake and left it un-hooked. there is no smoke comming out of it, like if i had blow-by
i just went out and took the oil cap off while it was running, and there is no smoke or oil pushing out of it at all
I can't speak much on the flames. You do have a clean out on your muffler to let residue out. I know that fuel starvation on the deutz is usually pretty obvious especially when the fuel pickup in the tank is clogged but that wouldn't account for it being too rich.. I don't think and I never saw flames when that happened and the backfire didn't last long as the deutz quickly died. I have seen a lot of the fuel lines get holes in them, though. They need to be replaced occasionally. I used to keep a handful of the rubber hoses in the shop and would just cut to fit when it was time to replace. But your symptoms were different. Check your air filter, too, make sure you aren't completely plugged.. That deutz wants clean air.
I would suspect a fuel injector not spraying properly. It is spraying and dribbling at the same time. Black smoke is no air or too much fuel. Since your air is open it will be the too much fuel. Loosening the injectors is not helping because the injector is working, just not properly. pull turbo back off, then exhaust manifold. You can pipe the oil pressure line for turbo to the return directly just for a short run time to test. Start machine and see if it is only one hole or more. Exchange that injector for a rebuilt one. I have seen a slight mixture of gasoline in the diesel tank give way too high of octane as well. Wasnt enough to cause a hard rattle or "fuel knock" but it definately had the diesel on steroids. If all holes are smoking equally it could be this. Last thing would be the timing. If the fuel pump is out of time the diesel is not atomizing properly on the piston during piston rotation and not giving a proper "burn" or combustion in the chamber. This will allow it to run and not burn diesel properly as well. If nothing looks tampered with around fuel pump i would lean towards injector. Even though the timing could be off internally it is the less likely scenario. It doesn't cost anything to run engine with clean diesel out of a bucket to eliminate gas in diesel. Other than maybe a few gaskets it doesn't cost much to pull exhaust manifold to see if it is just 1 or 2 injectors. Try these first. Good luck.
I think JeremiahSr has it. Sounds like something other than Diesel in your Diesel.
well, i got a guy comming to diagnose it on monday,, so, in the meantime, i'll just keep running the other 873
also, anyone have the part number for injectors? thanks
ok guys. a buddy of mine so happened to have parts from a machine he worked on some years ago, and i got an injector from him. i started woth the cylider closest to the timing belt, and of course, once i got to the last one, it stopped smoking!. runs like a kitten now. i want to thank all you guys for the help and advice
"Black smoke = incomplete combustion. Causes typically from restricted air flow but you have checked that. Not sure the style of injector nozzle you have but another cause of black smoke can be an injector or two cracking early, basically leaking under low pressure. Another cause of incomplete combustion. Also at an idle or no load condition you may not totally notice an rpm issue but under load should notice engine missing. This would also give you the issue of raw, unburnt fuel in the exhaust system." Glad you got it figured! Z