Quote:
Originally Posted by jmcc
Diesel engine controls don't add fuel when they're cold as a strategy, they put in whatever fuel is required to deliver the torque demanded by the driver/vehicle. So, cold start means more losses so to achieve the required torque more fuel is added. If the ECU detects a cold engine but in truth it isn't it will only add the fuel needed to run. Thd only problems you may have are if the idle speed setpoint is raised for cold conditions. Otherwise there will only ever be the right amount of fuel to run the engine.
For a diesel to overcome rough cold idle it would back out EGR ANC advance the timing. It might increase pilot injection and raise rail pressure, but it won't change main fuelling significantly.
This is in contrast to a gasoline engine which CAN alter the fuelling under cold conditions, generally to help cat light off. The gasoline engine will limit the air or retard the timing and lose efficiency.
FC = fuel consumption, sorry!
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Check out some of this information on a modern diesel engine:
http://api.viglink.com/api/click?for...13324324882321
page 46 has some interesting information on start fuel quantity as it relates to cold conditions. There are also varoius other pages describing how the fueling system uses coolant temperature, fuel temperature, and intake air temp to control injected fuel volumes.
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