Dodge D250 1990 - Fuel System Components and Flow; Fuel System Specification Dodge Ram 5.9 Liter Diesel

Fuel System Components And Flow Fuel System
Page 14-2 DODGE Turbo Diesel
Fuel System Components And Flow
The following illustration identifies the components of the fuel system.
The engine is equipped with a cam-actuated lift pump. Fuel flow begins as the lift pump pulls fuel from the supply
tank. The pump supplies low-pressure fuel (21-35 kPa, [3-5 psi]) to the fuel filter head, through the filter and then to
the distributor injection pump.
The engines use distributor-type fuel pumps supplied by Robert Bosch.
The distributor pump builds the high injection pressures required for combustion, and routes the fuel through
individual high-pressure fuel lines to each injector.
When the high-pressure fuel reaches the injector, the pressure lifts the needle valve against the spring tension to let
the fuel enter the combustion chamber.
Any leakage past the needle valve enters the fuel drain manifold. The fuel drain manifold routes controlled venting
from the distributor injection pump and leakage from the injectors back into the fuel tank.
1. Fuel from Supply Tank
2. Lift Pump
3. Low Pressure Supply Line
4. Fuel/Water Separator Filter
4A. Fuel Heater
4B. Fuel/Water Drain Valve
4C. Fuel/Water Separator Filter
4D. W.I.F. (Water in Fuel Sensor)
5. Thermistor
6. Bleed Screw
7. Low Pressure Supply Line
(Robert Bosch)
8. Robert Bosch VE Distributor
Type Injection Pump
9. Turbo Boost Control Line
10. Control Module
11. Fuel Drain Manifold
(Return Fuel to Tank)
12. High Pressure Lines
13. Robert Bosch, 17mm, Closed
Nozzle, Hole Type Injectors
14. KSB Valve
15. Manual Shut Down
16. TDC Timing Pin
Note: #10 Controls Intake Heater,
KSB, Fuel Heater, WIF.
Fuel System Specification Dodge Ram 5.9 Liter Diesel
Maximum Allowable Restriction to Lift Pump with Dirty Filter - mm Hg [in. Hg] 95 [3.75]
Maximum Allowable Return Line Restriction - mm Hg [in. Hg] 518 [20.4]
Maximum Allowable Pressure Drop Across Fuel Filter - kPa [psi] 21 [3]
Minimum Allowable Lift Pump Volume 0.75 liter [0.70 U.S. quart]
Note: Within 30 seconds
at cranking speed.