# Diesel starts then dies.



## beastmaster

I put the clutch in, and go to fire her up it fires , purrrrs, then dies. Then won't start. Let it sit for an hour it'll do the same thing. Its a Caterpillar diesel in a morbark 2400.
I don't know much about diesel. I check the oil leval, i cracked each injector tell fuel shot out, thinking there could be air in the system. I drained the water separator thing. Thats about the extent of my ability. Any guesses or advice on what it could be?


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## blades

Only thing that shuts a diesel down is lack of fuel - Have you changed the fuel filter? If not do so and fill it prior to reinstalling it.


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## Marshy

Video might help.


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## Greg Moore

If it starts it isn't likely air in injection lines, normally won't start at all or will start but run horrible. Does it stumble as it dies or just shut off? It will have a low oil pressure kill and an over heat kill. The low oil pressure kill _may_ have an automatic 'ignore' for several seconds after start then will be put into the circuit. It's designed to stop fuel flow if oil pressure drops and of course until the engine runs for a couple of seconds there isn't pressure so they ignore that sensor.. When they fail (or your engine fails to build enough oil pressure) then it will start, then shut down.. Usually should allow restart almost right away though 

There will also be 2 fuel pumps, one is the injection pump, probably not at fault, the other is usually referred to as a lift pump, it has to get fuel from the tank to the injection pump, if it failed or weak it will shut down or run horrible. Another cause for both gas and diesel is plugged vents to the fuel tank, as it runs, if air can't replace the used fuel it will stop drawing fuel, that usually takes several minutes.

You don't say if it runs for 10mins, 10 seconds etc etc, makes a difference but if it starts and runs good then quits in seconds, you're probably into a safety feature designed to protect the engine. If it starts and runs for several minutes theyn probably a fuel flow issue, filter, pump, vent, squished fuel line etc.


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## capetrees

Is it very cold where you are? Diesel gels and won't allow the engine to continue to run without additive. How's your air filter? Old? Mice living in it?

Then there's something called a Murphy switch. I believe it's something on the engine that shuts it down to prevent damage like low oil pressure, high water temp, low water level, high oil pressure, etc. How to fix or check? Don't know.


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## capetrees

Check your fuel line too for any kinks or clogs that wouldn't allow the pump to keep up with the need. And of course your fuel filter. May have enough to run for a little while but clogged enough to slow the fuel feed.


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## ChoppyChoppy

What's the temp? Do you have it plugged in? Did you do anything to it before? (Ie... did it run fine yesterday and now it won't)


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## bplust

blades said:


> Only thing that shuts a diesel down is lack of fuel - Have you changed the fuel filter? If not do so and fill it prior to reinstalling it.



Or lack of air (like the mechanism a Detroit uses as an emergency override).

Unless you're a long way from home, I doubt temperature is your issue.

Replace or clean your air filter. Replace your fuel filter if you can't remember the last time you did it. Additionally, look for any leaks on the pickup side of your fuel pump. Cracks in lines, loose filter, loose hose clamps, etc. A tiny amount of air introduced to the pickup side of a diesel can cause horrible running conditions or a complete "no-go". Dirty fuel could be a culprit as well. Nothing replaces a new set of properly balanced nozzles, but I will say that when it's the right serum for the ailment, a can or two "Diesel Purge" can make quite the difference. Again, this will not give you new nozzles or a new IP, but it will give you a good cleaning if your nozzles are old enough to vote.

Also, as others have mentioned, check your low oil shutoff.


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## blades

well he is in Comiefornia so temp/ gelled fuel isn't issue. It is on a chipper so air cleaner. Bad fuel possible but it starts runs a bit dies so that signifies either fuel lift problem, lines or the oil pressure/ or sensor for low oil pressure. he didn't state the age of unit only the particular eng. which I am not familiar with. It would be nice to know age as that would ref. which emission systems it might have if any and any computer control systems. It could have a plugged screen on the lift pump inlet also or just a shot pump. As it is a chipper there are other safety switches involved as well. Anyone of which can cause a shutdown by shutting down the lift pump. I do not think that is the issue though as he stated almost an hour before he could restart it, which sounds more like clogged fuel system or as was stated air entering fuel lines somewhere. I had a gasser that the fuel pump went intermittent similar senario start run a bit then die. Sometimes it would run for a couple hours then die. couple hours later you could repeat, but no restart right away after it died. That caught me in the middle of know where, got a little pricy having it dragged back to shop where I promptly replaced fuel pump. ( pump in tank- full tank- that was fun draining 25 gallons out to drop tank)


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## beastmaster

Im in Albuquerque now. Its the coldest place ive ever lived. I notice when i drained the water separator the fuel that came out seemed really thick. Also thou the oil level was good, it was thick as crude oil.
the chipper has been sitting for like 8 months, does diesel go bad.
Guys tell me it was acting up before the clutch got fried, but it ran.. when it starts it sounds good, then maybe 10 seconds it just stops..


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## 2dogs

I would drain all the old fuel and look in the tank. If there is any sludge then pull the tank and flush it. Consider adding an in line filter between the tank and the lift pump. If the lift pump fails it can starve the injection pump and cause thousands of dollars in damage in a few minutes. Change the cheap lift pump and the main filter/water separator. If there is a Murphy switch then bypass it for the test run. Same for the ignition switch. Low oil or high temp shutdown switches. How does the engine shut off? Electric solenoid? Pull the muffler and make sure it hasn't collapsed.

Then just change the oil, change the hydraulic fluid, clean the strainer, swap out the filter, sharpen the blades, pull the bed knife and have it ground, adjust the bed knife, adjust the feed roller tension, grease the bearings, make sure the lights work, air up the tires, and get your lazy ass to making money!


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## earlthegoat2

For symptoms like that, my first thought is the fuel filter, water separator, or both. Some units have a combined filter and water separator. On those, I have never had much luck just draining them. That seems to be only a temporary solution. Might be different for you though in that drier climate. Over here, moisture is a problem with all fuels.


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## eastsidetimber

Check your murphy switch before anything. It's cheap and it sounds like the issue to me. Had the same problem just the other day on my 2400


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