Prior to this, most diesel engines used an injection pump that measured fuel and delivered it to each injector, often known as a Pump-Line-Nozzle system (PLN).

The advent of electronically controlled, independent injectors was another one of its contributions. The value is updated every engine revolution with the Power Stroke. With the Power Stroke, injection timing was completely flexible: there were timing maps (lookup tables) that changed the injection timing for any altitude from sea level to 10,000 feet, for any oil temperature from -10☌ to +290☌, for any boost from zero to 21 PSI, and for any injected fuel amount from zero to 100 mg/cyl. It was lowered to 0 PSI before being raised to 25 PSI of boost, where it remained stable for miles and miles. It was 12* at -20*F below zero and 12* at 250*F engine coolant temperature. At idle, you set it to 12* BTDC, and it stays at that setting until 3,000 RPM.

Diesel injection timing has been effectively fixed since then. The standard today is a computer-controlled diesel it was previously revolutionary. It’s main distinction at the time was that it was the first diesel engine sold in the United States to be computer-controlled.

Other than their displacement of 7.3 liters, not a single component is identical. The 7.3L Indirect Injection was regarded as the successor to the 7.3L Direct Injection, despite the fact that they have no components in common. The 7.3L Power Stroke engine was introduced in the summer of 1994. All IDMs are completely swappable / interchangeable between all model years of trucks, vans, and Excursions. There are three distinct circuit board designs among these four IDM models, as well as several additional minor changes. There are four primary versions of IDM: the EDU-100A from 1994 to 1995, IDM-100 in 1996, 1997, and 1998, IDM-110 in early 1999, and lastly the IDM-120 used in late 1999 and later vehicles. The connector pinout of T444E IH IDMs cannot be interchanged with 7.3 Power Stroke IDMs due to differences in the layout of connector pins. The International 7.3 Power Stroke IDM and the T444E two-box (separate PCM and IDM) trucks used almost the same identifier, but there was no vent in the case. The majority of IDM’s are killed by this, and since a large number of the cores we receive back are non-rebuildable, this causes costs to go up. Water is able to enter through the vent as well, with no means to expel it. They’re all well-designed machines, except for a vent in the case designed to allow for pressure changes owing to elevation or temperature swings. It has limited diagnostic functions for detecting short or open circuits and transmits any faults to the PCM using a basic serial link. The IDM (Injector Driver Module) is a simple device that fires the injectors in response to a signal from the PCM, informing it which injector to activate.

Ford 7.3 injector driver module