S470D won't start/run

[Steve777]

Well my old reliable Buck has let me down for the first time in many years. It was running fine 4-5 weeks ago when I last used it. I went out today to do some snow plowing and the engine had a lot of trouble catching first time, but it did finally start. Let it warm up for a min or two and then tried using the hydraulics and that killed the engine (just trying to lift the rear blade). OK, I figured it was a fuel problem, so I checked the filter, put some diesel 911 in (it has been cold the last few night, 0-5F, but it was 35F today) and there might have been some gelled fuel in the lines or IP I thought. Fuel seems fine, very liquid and free flowing out of the filter body. Bleed the fuel lines (they seemed full).

Now I can crank for a long time but not getting the engine to catch. It is blowing white/grey smoke as I crank, so I think fuel is getting to the cylinders. But it doesn't catch or run without the starter.

I'm at a loss as to what else it could be. I suppose the glow plugs might have died, but at 35F, with long cranking times (30+ sec) it should have caught I would think. I've got the battery charger on it now, and probably can take one more shot at starting it later today. But I'd be interested in ideas of what to check.

TIA

 

[techwrtr2]

Don't assume you're getting fuel. I still haven't gotten my Beaver to start (too cold to work, space too cramped) and I also get some smoke as it cranks. I disconnected the lines from the injectors and well, almost nothing. Found this out back when it was a lot warmer than it is now. Verify you have good fuel flow at the injectors when cranking and the throttle is set to max. I'm strongly suspicious of my injector pump but before I spring for a new/rebuild, I want to be as certain as I can that there are no other issues.

Verify your glow plugs are getting juice when you try them. I think you can safely test them out of the block as long as you have a ground to them but don't quote me on that.

 

[Ilikeurtractor]

I'd second the glow plugs as the culprit. At least for a first check. I'd highly recommend investing in a DC clamp meter (<$50 if you look around). Check the wire feeding the glow plugs. It should be 35-45A for a three cylinder with all the glow plugs working. Check individual wires to narrow it down further. Without glow plugs you'll end up cranking much longer than you may think would be required, even at 35 deg F which really isn't that warm for a diesel.

 

[Steve777]

Thanks. Well I left it on the charger and sitting in the sun for another hour and tried again. Had to crank for a while, but it did catch and run. I let it warm up for 5 mins or so, just to be sure it would keep running. Not that that is a guarantee, but it did seem to work. The engine ran perfectly and I finished the plowing without incident.

One thing I noticed, as it was warming up, there was a definite point when all of a sudden the engine seemed to run better. The RPMs sped up and I had to turn down the throttle to keep it at a reasonable idle speed. At the time, I thought that a "glob" of gelled fuel melted and things got back to normal. But I did not really investigate further. It wasn't as though any cyl was missing before this event, just that the engine wasn't running as fast as it normally would at that throttle setting.

I obviously have some work to do on this tractor once the weather improves. Checking the glow plugs is high on the list. I do think they might be to blame for the long cranking times. But I am curious to get people's thoughts on the "glob" theory. Not sure if it really was a glob of gelled fuel, but perhaps some part of the IP was stuck for whatever reason and broke free after running a bit. Do these symptoms sound familiar to anyone? Any ideas?

 

[Ilikeurtractor]

The white and/or light gray smoke you're getting while cranking indicates insufficient heat for combustion. If it eventually starts it's probably not a restriction in the fuel line. Of course, if the "glob theory" is true it should subsequently start right up after returning to a cold condition (of around 35 deg F at the block) so it would be easy to test. I've never seen an IP "stick" as far as the plungers in it, but I suppose it could be possible. When it's running rough you could crack each fuel line at the injector and see what difference it makes. If one line doesn't seem to make much difference it could be an IP issue, but you probably wouldn't see any fuel leak out when the line is cracked either. It could also mean leaking cylinder valves and a problem with the injector also.