Dodge D150 1990 Service Manual page 686

FUEL DELIVERY SYSTEM
INDEX
Page
Fuel Filter
6
Fuel Hoses and Clamps
7
Fuel Pump 3
FUEL PUMP
The fuel p u m p used i n t h i s system has a perma-
nent magnet electric motor. The p u m p i s p a r t o f the
fuel pump module located i n t h e f u e l t a n k a n d i m -
mersed i n t h e fuel ( F i g . 1). T h e fuel i s d r a w n i n
t h r o u g h a filter and pushed t h r o u g h t h e electric mo-
tor t o t h e outlet. The p u m p contains a check valve,
located near t h e p u m p outlet, r e s t r i c t i n g fuel move-
m e n t i n either direction t o m a i n t a i n fuel supply l i n e
pressure when t h e p u m p is n o t operational. Voltage
to operate t h e p u m p i s supplied t h r o u g h t h e A u t o
Shutdown Relay.
WARNING: THE TBI FUEL SYSTEM IS UNDER A
CONSTANT PRESSURE OF APPROXIMATELY 100
KPA (14.5 PSI). BEFORE SERVICING THE FUEL
PUMP, FUEL LINES, FUEL FILTER, THROTTLE
BODY OR FUEL INJECTOR, THE FUEL SYSTEM
PRESSURE MUST BE RELEASED.
Perform fuel system pressure release procedure be-
fore servicing t h e fuel p u m p .
PRESSURE RELIEF/
_ _ _ _ _ ROLLOVER VALVE
ELECTRICAL
TERMINAL
FUEL
RESERVOIR
FUEL GAUGE
SENDING UNIT
RR14G218
Page
Fuel Pump Module 4
Fuel Pump Pressure Test 3
Fuel System Pressure Release Procedure 3
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
(1) Loosen fuel f i l l e r cap t o release fuel t a n k pres-
sure.
(2) Disconnect injector w i r i n g harness from engine
harness.
(3) Connect a j u m p e r w i r e to ground t e r m i n a l
N u m b e r 1 o f t h e injector harness ( F i g . 2) to engine
ground.
(4) Connect a j u m p e r w i r e t o t h e positive t e r m i n a l
N u m b e r 2 o f the injector harness (Fig. 2) and touch
the battery positive post for no longer t h a n 5 sec-
onds. T h i s releases system pressure.
(5) Remove j u m p e r wires.
(6) Continue fuel system service.
TERMINAL #1
TERMINAL #2 8914-123
Fig. 1 Fuel Pump
Fig. 2 Injector Harness Connector
FUEL PUMP PRESSURE TEST
WARNING: THE TBI FUEL SYSTEM IS UNDER A
CONSTANT PRESSURE OF APPROXIMATELY 100
KPA (14.5 PSI). BEFORE PERFORMING THE FUEL
PUMP PRESSURE TEST THE FUEL SYSTEM PRES-
SURE MUST BE RELEASED.
(1) F u e l system pressure m u s t be released prior t o
servicing a fuel system hose or component. Perform
fuel system pressure release.
(2) Disconnect t h e 5/16 diameter fuel supply hose
f r o m t h e engine fuel line assembly. Use care w h e n
r e m o v i n g t h e fuel hose t o prevent damage to t h e
hose or t h e fuel line. Replace hose i f damaged. Con-
nect fuel system pressure tester C-4799A between
fuel supply hose and engine fuel l i n e assembly.
(3) U s i n g diagnostic tester, w i t h t h e key i n t h e
" R u n " position, use Actuate O u t p u t s Test " A u t o
Shutdown Relay", this w i l l activate t h e fuel pump