Thread: Tuning Experience Levels?
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Old Wed, March 31st, 2010, 05:37 PM
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Originally Posted by theSLEEPER View Post
OK. I'm getting it now. MFD is TPS input, based on how the pedal is scaled? And 21 MPa is 3045psi?

OK. If that's right... I'm somewhat confused again...

On your 3D fuel injection PW table, it looks like ICP is going down as throttle input and PW is going up? Is that right?

Here are a couple nondescript scenarios that get to the same point.....

If the ICP is raised from 1400 PSI to 2500 PSI, the actual commanded pulse width HAS to decrease to maintain the same MFD. This is because a higher ICP is going to cause an injection of more fuel at higher pressures for a given pulse width.


If the Mass Fuel Desired is raised with a constant ICP, then the pulse width HAS to increase. It is not possible to inject more fuel while keeping a constant ICP unless the injector is commanded to squirt more fuel.

Don't get hung up on thinking that Mass Fuel Desired is another term for accelerator pedal position......
The MFD map is based on accelerator pedal position and RPM.

This is enough to make a guy crazy sometimes!!
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Tuning, PCM flashing, and burning chips for 7.3s since 2008. Repairing all aspects of 7.3L Powerstrokes for 25 years.
Eight 7.3L PSDs in the driveway including a 1994 Crown Vic and 1973 F100/2002 F350. Looking for the next victim.
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