Hard Starting Boomer - HELP

[MeanGreen]

Hope one of you can help me with a problem that has resisted fixing. I have a NH 1925 with 650 hours on it (34 hp Shibura). It has been very reliable until recently. It always started on the first try, but now it won't fire up without a touch of ether. After it starts it runs fine. Here is what I tried so far:

1. replaced the battery
2. replaced the battery clamps (they were badly corroded)
3. replaced the diesel fuel and the fuel filter
4. tested the glow plugs with an ohm meter (dealer said it should be > 1-1.5 ohm resistance)

Now, here is how it goes. I let the glow plug light on for about 15 seconds, then I try to start the tractor. It turns over and puts out dark smoke but does not fire at all. My recollection is that it seems to turn over somewhat slowly now, but it has a new battery and connectors; then again it could be just my bad memory. If I shoot just a touch of ether into the air intake (with filter still in place), she will usually catch and fire right up. At that point I get a good deal of dark smoke initially and then she runs fine for hours. If I turn her off the whole tough starting process starts all over again. I am pretty much a diesel engine novice so I need to ask the experts if there anything else I need to look at? Please help.

 

[Bird]

I'm not a mechanic and can't say what the problem is, but I'll say one thing; you've got a lot more nerve than I do if you shoot ether into the air intake on a diesel engine that has glow plugs. And if that has worked without causing a problem, then I'd suspect the glow plugs are not working.

 

[Soundguy]

Once you get it running.. pull the oil dipstick.. is there alot of compression blowby/ some will be normal for a diesel.. lots will make for hard starts..

Soundguy

 

[Soundguy]

We lovingly call that stuff head bolt loosening fluid...


Soundguy

 

[loner]

Are your air filters plugged way up? You giving her a little throttle while cranking ? Maybe she ain't turning over fast enough" starter"

 

[jinman]

It sounds to me like your glowplugs may be good, but you may not be getting any current to your glow plugs. I'd hang a voltmeter on the glowplugs and see if the voltage cycles on. You may have something as simple as a blown fuse or a loose connection.

With the symptoms you described, that sounds like the most likely problem to me.

 

[MeanGreen]

Thanks Guys, to answer a few questions,
1) very very little ether,
2) I will check the "blow by" tomorrow but my question is what does it indicate if you have excessive compression,
3)the filters are nearly new - I did the 600 hr PM late last year,
4) I am not sure exactly what I am looking for on the voltmeter, but on a related note, I wonder if I would have the glowplug light if I was having an electrical problem or blown fuse (it has had some previous electrical problems by the way)?

Great suggestions, keep them coming!

 

[jinman]

MeanGreen, disconnect the lead going to one of your glowplugs and hook it to the positive lead of your voltmeter. The other lead goes to ground. Set the voltmeter on the 25 volt DC or 50 volt DC full scale range. Cycle the glowplugs and see if the meter deflects and the reading (It should be 12 to 13 volts). Reconnect the glowplug, leaving the meter connected, and cycle the glowplugs again. The voltage might drop a couple of volts (since the glowplug pulls a lot of current), but not much more. Do this on each cylinder to ensure they are all cycling.

Since you say the problem happened all at once, I think all your glowplugs are not working. The chance of them all going bad at the same time is pretty slim, so I suspect a wiring problem or a fuse (maybe even a bad or loose relay). I'm not sure of the wiring on your tractor, but I would look for a fuseblock and maybe an inline fuse. If it were my tractor I would probably try to hook up a jumpered bypass to the glowplugs, but you should not try this if you are not skilled with electricity.

Your glowplug light might be on a parallel path to the glowplugs and not be a true indicator of their operation. By using the voltmeter, you can find out if the glowplugs are being powered properly.

Good luck and try not to become frustrated. /forums/images/graemlins/smile.gif

 

[JerryG]

<font color="blue">If I shoot just a touch of ether into the air intake</font>
Your glow plugs may not be working. If they were and you shot either in there, there is a good chance that you would detonate the engine. Glow plugs (indirect injection diesel) and either are a very hazardous combination. Either should only be used in direct injection engines.

 

[djradz]

Although the discussion so far has centered around the glow plugs, and that truly might be part of the problem, it only would have an effect on cold-starting the engine. Your initial post noted that the problem starts all over again when you shut the engine off. Do I understand you right when you say, <font color="blue"> "If I turn her off the whole tough starting process starts all over again." </font> to mean that even if you turn the engine off and immediately restart it, now when it's warm, the problem occurs. If so, there's got to be more than the glow plugs malfunctioning. If that's the case, I think I'd start considering injector pump problems, but I'm no expert either. /forums/images/graemlins/confused.gif