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720 diesel, rough start


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Hey guys! 


I have a 1982 720 diesel that runs great when it's warmed up.


It throws some rich white smoke at cold startup and struggles to get going. It has gotten worse with time. Smells like improperly burnt diesel, luckily not sweet. I figured it must be the glow plugs, so I replaced them. Still an issue.


I tested the battery, glow plug wires, and alternator with a multi meter. They all read just fine, but when I turn it over, it takes a while to get to a positive operating voltage.


It's got some electrical issues with the fan not working at full blast and the cigarette lighter adapter doesn't work. Fuses are all fine, but maybe the box/ connections?


Anywhere else I should look into? Ignition maybe?


Thank you!

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I have issues this time of year starting my diesel also, they just don't like starting when it is below 40 degrees and when they do run white smoke comes out the tail pipe every time a cylinder doesn't catch fire/ignite, I have been dealing with this for years, I have a block warmer and if I plug it in a hour ahead of time it fires right up without issues, I also have been experimenting with an "Air Heater Element" over the past month, it seems to help mine start easier.

My SD22 series engine hasn't even wanted to start if it is below freezing in the past on engines without block heaters, so now all mine have block heaters, and like I mentioned I am trying the "Air Heater Element" route, I will know more when I try it in the 20s, it just hasn't got that cold since installing it.

Here are a couple links to my threads about my diesel engines.

Last page of this thread where I am trying out the "Air Heater Element"


My diesel truck thread at the Nissan diesel Forums.



Keep in mind here that diesel engines do not like starting when it is cold out, and it has nothing to do with the glow plugs, it's just too cold so they need some kind of help, and starting fluid is not a safe type of help!!!

Edited by wayno
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6 hours ago, wayno said:

Maybe the injectors are getting worn out and not atomizing the fuel like they used to.


I think you nailed it perfectly sir. I grew up in a family of diesel mechanics and the white smoke/ hard to start was common with old worn injectors.

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