As anyone familiar with diesel engine operation knows, a diesel engine differs from other liquid fuel engines in one major respect: The fuel/air charge is ignited by cylinder pressure and heat, instead of via an electrical ignition system (diesel-fueled engines don’t use spark plugs).
On its downstroke, a piston draws air into the cylinder. On the compression stroke, the fuel injection system (depending on how it’s timed) spits fuel into the combustion area, and the resulting cylinder pressure (and residual heat from previous firings) combusts the fuel/air mix, etc.
Diesel heads generally don’t feature combustion chambers (flat decks with no chambers). Instead, the combustion chamber is afforded by the piston’s “bowl” cavity. Partly because of the serious cylinder pressures and forces exerted on the bottom end, diesel components (blocks, cranks, rods, pistons) are, for lack of a better term, heavy-duty and very beefy in construction. As compared to gas engines, just about everything on a diesel is bigger, heavier and more massive.
Ford’s Powerstroke diesel engine lineup includes a series of V8s. While the engines were built by International, Ford’s chosen name for their diesel engines is Powerstroke. The naturally aspirated International 6.9L/7.3L IDI (indirect injection), from 1982 to 1994 (the 6.9L ran from 1982-1987, and the 7.3L from 1987 to 1993. Starting with mid-1994, they switched to the turbocharged Navistar 7.3L, which was used until early 2003.
The Navistar 7.3 turbo engine was an outstanding engine platform. Then came the Navistar 6.0L turbo from 2003-2007. This was followed by the twin-turbo 6.4L from 2008-2010. The 2011 model features a Ford-built 6.7L single-turbo diesel. Cylinder heads are cast iron, except for the 6.7L, which features aluminum heads and a strong CGI (compacted graphite) block. Well over 2 million of the 7.3L engines remain in service today.
Powerstroke tech tips
SHORT IN INJECTOR
Some 2011-2012 F-Super Duty vehicles equipped with the 6.7L diesel engine may exhibit DTC P1291 and/or P1292 due to an internally shorted fuel injector. An internal short in an injector may be caused by fuel being contaminated with DEF (diesel exhaust fluid) or by fuel gelling.
Remove the fuel conditioning module mounted filter. Allow the filter and filter bowl to dry for at least two hours. If the filter turned white, this indicates that the fuel is contaminated by DEF.
In this case, the complete high pressure fuel system and diesel fuel control module (DFCM) needs to be replaced and the system flushed.
If the filter did not turn white, inspect the wiring harness for chafing near the EGR cooler. Repair the harness as needed. If no chafing is found, disconnect each fuel injector electrical connector for injectors 1, 4, 6 and 7 (for P1291). Disconnect injectors 2, 3, 5 and 8 for P1292.
Check for continuity between the injector electrical pins and the injector body. If continuity is present, replace the injector(s) and the injector(s) return hose.
Injector return hose BC3Z-9A564-A
Fuel injector (cyl 1, 2, 7, 8) BC3Z-9H529-A
Fuel injector (cyl 3, 4, 5, 6) BC3Z-9H529-B