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Old 08-05-2008, 02:20 AM   #6 (permalink)
Yoshi
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Quote:
Originally Posted by dcb View Post
So it may work, it depends on the duration of that initial squirt.
Do you have any clue how much the "Injector DelayuS" value would be?

add note:
The MPGuino program assumes the fuel pressure is constant thus the fuel usage is proportional to the injector ON time.
The article says...
Quote:
Unlike a petrol injection engine where fuel pressure is held a constant headroom above intake manifold pressure, in the HDi engine, fuel pressure varies with engine speed. Thus, at idle quite long injector opening times are used, because the lower fuel pressure means that there is less flow for a given pulse width. At higher engine speeds the time available to inject the fuel is less and so the injector opening times must be shorter. To squeeze the greater amount of required fuel through the injectors, the fuel pressure must be high. In fact, the 3D fuel map of the ECU uses these axes: fuel pressure, engine speed and fuel flow. In addition, other 3D ECU maps exist for the:
(snip)
I believe we have to have a kind of "3D fuel map" inside of the program to see an accurate fuel usage.

Yoshi

Last edited by Yoshi; 08-05-2008 at 02:41 AM..
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