Was going to start a new thread but found this one to jump on.
Having hooked up techstream for an analysis I noticed the fuel temp was 57 deg C (fuel tank full - rational for mentioning this will be evident further down)
The vehicle was stationary and Intake air was 40 deg.
Fuel System.PNG
Given the location of the fuel temp sensor I am assuming it reads fuel supply temp - not return fuel temp.
It got me thinking about the fuel cooler and what the return fuel temp should be to prevent condensation, water in fuel and engine failure.
The more I looked the more it seemed like opening a can of worms...
A few related links and interesting reading:
http://www.newhilux.net/forum/viewtopic.php?f=29&t=13035http://www.newhilux.net/phpbb/viewtopic.php?f=8&t=423http://www.berrimadiesel.com/home/cool-fuel/VMN wrote:Just catching up on this thread again. In relation to the fuel cooler, it is my understanding that it is on the return line to the tank so it cools the diesel after it goes through the common rail at up to 156,000 kPa (thats about 22,500 psi before anyone asks). Becasue of this, I don't think you will see a significant change in temps between Brendon's engine fuel temp and those we have with the fuel cooler unless you were running on empty.
Snip:
"Because of the extremely high fuel injection pressure, the fuel in the return line becomes very hot, and a fuel cooling system is used to cool the excess fuel before it is returned to the tank. Besides the obvious effect on safety, if the fuel was not cooled, the fuel temperature in the tank would rise, which in turn means that the temperature of the fuel supplied to the injectors would also rise. Under high-pressure injection conditions, hot fuel reduces fuel delivery from the injectors; although the ECU can compensate to a reasonable degree for fuel temperature variations, cool fuel gives improved combustion and hence improved engine efficiency."
Snip:
"The common rail systems create high fuel temperatures (up to 90 degrees C ). They also have very high fuel flow rates for cooling (up 60 litres per hour) at least 80 percent of this fuel is returned to the tank passing through fuel coolers. "
P1020408.JPG
This road pic was taken before peak temperatures reached. Not suggesting this is the ambient air temp but the fuel cooler is only a foot or so from the road surface.
Given the returned fuel can reach over 80 degrees and many parts of the world can reach over 40 degrees ambient air temp what temperature difference can the D4D fuel cooler achieve?
Can the cooler cool the returned fuel down in hot climates enough to prevent fuel de-rating?
As the fuel tank is also a 'cooling tank' reservoir of sorts its probably another good reason not to run too low on fuel...
You do not have the required permissions to view the files attached to this post.