So what does it REALLY do
What's the REAL Benifits, I have an early 99 an I'm sure mine could be worn out
As the IDM becomes older and older the distance or wave length becomes longer and longer which will greatly reduce performance and mileage if it gets bad enough. So rebuilding it basically puts it back where it should be, then they go and increase the voltage, resulting in a more crisp activation of the solenoid on top of the injector. When the voltage is increased that shortens the pulse width backdown, so the frequency is increased to counter balance that.
All in all, resulting in better throttle response, less injector noise, smoother idle, more power up top with larger injectors. The modification is noticed on stock injectors, but gets even better the larger you go.
Something I would suggest for anyone that owns a 7.3.