(PEEC) System Overview The 3406B PEEC Diesel Truck Engine is an electronically-controlled 3406B. The Electronic Control Module (ECM) for the engine controls fuel rate and timing electronically instead of using the flyweights and linkages of a mechanical governor. The electronics also replace the mechanical fuel-air ratio control, torque control group, and various adjustment screws.
The 1.1 liter engine fuel system utilizes a mechanical unit injector combining both the nozzle assembly and the high pressure fuel injection pump. The fuel transfer pump) pulls fuel from the fuel tank through an in-line primary filter and sends fuel to a spin-on type secondary fuel filter. From the fuel filter, fuel enters a […]
A fuel shutoff solenoid is located on the rear of the governor. There are two types. One is energized to run, the other is energized to shut down. The one shown is an energized to run solenoid. When the engine’s electrical system is energized (key on), the solenoid is activated
The fuel ratio control mounts on the rear of the governor housing. Its purpose is to limit smoke and improve fuel economy during rapid acceleration. It does this by controlling rack movement in the fuel ON direction until there is enough (boost pressure) to allow complete combustion in the cylinders. With the fuel ratio control […]
Governor Operation At the point the rack screw (green) first comes in full contact with the torque spring, the rack is at full load point (rated). As demand horsepower increased, with the rack at rated position, the engine speed decreases as the engine goes into lug (full throttle with rpm less than rated rpm).
3406 Fuel Manifold Cover The high pressure fuel that exits through the spill ports goes through the hollow dowel into the fuel manifold and hits the cover plate. These highly pressurized fuel pressure pulses cause polish spots that are lined up with the spill ports on the manifold cover plate of the 3406B/C fuel system.
3406 Injection Pump The area shown in red is the fuel gallery of the 3406B/C fuel pump. This area is pressurized by the fuel transfer pump. The cutaway shows the placement of the pump groups within the pump housing. Fuel enters and leaves the pump group by way of the hardened hollow dowel. This dowel […]
The fuel transfer pump is located on the bottom of the 3406B/C pump housing and on the side of the 3304B or 3306B/C pump housing. It is activated by the eccentric on the fuel pump camshaft inside the housing and can deliver up to 51 gallons of fuel per hour at 25 psi.
Caterpillar 3406B Engine The Caterpillar 3406A was introduced in 1973. Since then, a number of changes have been made to meet the demand for an even more reliable and economical product, while meeting governmental regulations. The 3406B, released in 1983, is an example of these changes. The major change to this engine was the fuel […]
The cooling of an engine depends on the principles of conduction, convection, and radiation of heat energy in order to keep the engine running at the proper operating temperature. The coolant receives the heat that is conducted to it from the metal components of the engine; the engine block, the cylinder head, etc. The coolant […]