Before then, the injection timing on a diesel was essentially fixed. It's biggest distinction at the time is that it was the first computer controlled diesel engine sold in the United States.Ī computer controlled diesel is the norm now then it was revolutionary. Other than being 7.3 liters, not one single part is the same. It was considered to be the successor to the 7.3L Indirect Injection, although the only thing the two engines have in common is their displacement. The 7.3L Power Stroke engine was released in the summer of 1994. As far as their functionality, all IDM's are 100% swappable / interchangeable between all model years of trucks, vans and Excursions. Within these 4 IDM models, are three very different circuit board designs, and several more minor revisions. There are 4 main models of IDM's in chronological order they are EDU-100A used in 1994-1995 vehicles, IDM-100 used in 1996-1997, IDM-110 used in early-99 and IDM-120 used in late-99 and newer vehicles. T444E IH IDM's cannot be interchanged with 7.3 Power Stroke IDM's due do differences in the connector pinout. International used an almost identical IDM in the T444E two-box (separate PCM and IDM) trucks, but they did not have a vent in the case. This kills the majority of IDM's, and also means that a large percentage of the cores which we get back are simply not rebuildable, which in turns pushes up the price of an IDM so we can cover these losses.

The vent also lets water in, with no provision to let it back out. It has some basic diagnostic capabilities for detecting short or open circuits, and reports any problems to the PCM via a simple serial communication link.Īll in all, they are very well designed devices, except for a vent in the case intended to allow for changes in pressure due to elevation or temperature changes.

The IDM (Injector Driver Module) is basically a dumb box that fires the injectors in response to a signal from the PCM telling it which injector to fire, when to fire it, and for how long.

1994 f350 7.3 injector driver module