I've been a spectator on this forum, normally a 7.3 dude, and have seen issues with pilot injection. Don't know what it is and would like too.

Bill in KY 7.3 PSD'01 and happy.

 

The way I understand it, the injectors spray a small amount of fuel right before the full charge of fuel is sprayed. I guess this causes a more "controlled" combustion that keeps things quite

 

pilot injection means, at injection the injector is being controlled by a pilot (other means of operating the injector) some newer 7.3's i do believe have hydraulically actuated injectors, which are controlled electronically, not sure how the 6.0's are but i think they may be along the same line, having electronic over hydraulic direct injection, basically the pilot being the electronic part while the hydraulic part does the actual operating of the valve. hope this helps

 

A May 28, 2002 press release from Ford Motor Company: "Pilot Injection: By delivering small quantities of fuel into the combustion chamber prior to the main injection event, the combustion process is both smoother and quieter."

Same article states : "The new diesel will offer up to 10 percent better fuel economy and 20 percent lower emissions. The new diesel also has reduced noise levels and has improved speech intelligibility while driving by more than 20 percent."

Also found this information in a different article: "Leading these is the introduction of the first closed-loop control system for diesel engines, called Accelerometer Pilot Control (APC), which allows the Engine Management System to ‘analyze the quality of the combustion. Information from the APC allows injection to be adjusted as conditions change, ensuring that the system is always correctly calibrated.

The major benefit of APC, combined with Delphi’s new generation, fast-acting compact solenoid injector, is that it allows exceptionally precise control of pilot injection. These tiny volumes of fuel, injected before the main injection pulse, smooth the start of combustion, eliminating the pressure spikes that produce the ‘clatter’ associated with previousgeneration diesels.

Existing technologies can provide a single pilot-injection event with a volume of around 1-2 mm3 at low injection pressures, but typically suffer from reduced metering accuracy during their life on the car, at idle or higher pressure. Engine designers need both low pressures for a quiet idle and higher pressures because this allows cylinders to be fuelled more quickly and to have a better spray pattern, leading to improved torque and reduced smoke. The Delphi system allows pilot volumes across the pressure range that remain stable between injectors throughout the engine life."

The pilot injection on the 6.0 is controlled by the PCM whereas the split shot injection on some 7.3's is a mechanical funtion of the injectors.

 

Nice explanation Twin. Thanks

 

BTW, the Delphi article I quoted is just a descrition the pilot injection process. It's actually describing the fuel system for a Ford Focus in Europe. I understand the 6.0 PSD uses Siemens injectors.

 

How can you tell if you still have the pilot injection or not?