Diesel Warm-Up -- How Long -- Why?

[Jerry/MT]

How in the heck does that work?:confused2: Diesel should just rev up with more fuel since its full air allthetime.
larry

It doesn't increase the fuel, it increases the fuel/air ratio.

There is a valve on the exhaust that closes down when the engine is cold and gradually opens as the temperature increases. (I'd presume there is a controller that would open the valve if there was a sudden increase in demand for power.) It's kinda' counter intuitive. It throttles the air to increase fuel air ratio during warmup. I understand some people wire them up and use them for exhaust brakes. (See Powerstroke website)

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[Jerry/MT]

I thought it was the other way around ?

Nope, more fuel/air ratio, more temperature. You don't necessarilly have to add more fuel, you can reduce the air flow at constant fuel flow and have the same temperature effect.

 

[JerryK]

That would work. Some Dodge/Cummins owners use the exaust brake to load/heat up their motors. Espar makes a diesel fueled coolant heater that can be used for warming up a cold cab or adding heat to the system... I thought about installing one whilst I was still working for a living, but just retired instead.... Some of the Dodge/Cummins can have their 3 cylinder idle enabled which fuels only three of the 6 jugs.... makes quite a racket I have heard. I have never enabled mine.

Espar Heater Systems | A World of Comfort | FAQ's

..and a link to 3 cyl idle if you are interested..

2001 Dodge Cummins Diesel Cold Start 3 Cylinder Idle - YouTube