706 d

Since that I've run Cummins. direct start Cats Detroits 2 cycle and 4, Kubota and just recently a Mack. What I am curious about is what these guys recomend when all those diesels without glow plugs, start smoking on a cold morning. You come far enough north to find -20 to -30 degree weather , let that diesel you have been running for several hours, idle for 5 or 10 min. The engine temperature will drop to about 130 and yes they will all start smoking again at that point. I have in the past 20 years, become acquainted with diesels in trucks. On cold winter mornings you start them up and could warm them up for 20 min., but the heater will not generate heat until you start to work them, nor will they stop smoking until then if cold enough.

I will give an example. A person I know became incharge of receiving at a Supermarket. This person thought I will show those truckers who's boss. One morning when it was about -25F, this person decided to let the truckers sit out in the cold for about 30 min before receiving. The truckers kept engines running to keep warm, couldn't blame them. When the doors were finally opened, there was a light breeze blowing towards store from about 6 trucks. This receiving person complained about the smell of raw diesel going right through the supermarket. I advised this receiver that had they received these trucks hot off the highway, before they cooled down, this wouldn't have happened, as she wouldn't have had a line up waiting, and trying to keep warm. The guy at the dock had to shutt off his diesel, but the rest in line didn't. So much for bullieing a trucker.

This is precisely why diesels should not be left idleing in cold weather. The engine temperature will drop to a point where fuel is not burned efficiently, and it shouldn't be left running.

At the risk of sounding like a broken record, let me say this:

That old gal uses a low pressure diesel pump. That means that the fuel is not atomized enough to ignite at the lower tempreatures like your newer high pressure units do.

In other words, they cannot "start from cold" without some help.

Hence, the 12 volt glow plugs are used to preheat that combustion chamber to a tempreature whereby the fuel will ignite.

Now, if one glow plug is not working and the other five are, the engine of course, is still going to start; but that one cylinder is going to push raw fuel until the effect of the compression itself (a few cycles of the engine compression stroke) in that bad cylinder, raises the tempreature in that cylinder to the ignition point. I'm guessing this is why you are getting the smoke....but, I'm diagnosing over the phone here too.

The glow plugs are very easy to test: Pull all the leads off all of the glow plugs. Then with a test light, with it's lead attached to the POSITIVE battery voltage, touch each glow plug terminal with the pointer one at a time. If you find one that does not light the test light, that's your boy.

If you find a bad one, there are some tricks to changing it out sometimes....they have a nasty habit of carboning at the tip and even sometimes will swell to the point that they just will not come out.....but, this is another chapter. Let us know what you find.

Now, if you find that all are okay, then I will bow to all these other fine gentlemen here and the advice that they have already given you: Hold the button down longer before the crank, hold it thru the crank, and for a short while after she pops off. But, you shouldn't be getting an excessive amount of smoke.

Regards,

Allan

I'd check the glow plugs. I'll bet one of 'em isn't pulling it's weight. Very common on these old systems.

Allan