Dodge ram truck 3500 1996 Service Manual page 1282

1 4 - 4 8 FUEL SYSTEM ~~ _ _ _
DIAGNOSIS A N D TESTING (Continued)
BR
Fig. 50 Map Sensor —8.0L Engine
(18) Verify harness connectors are firmly con­
nected to Idle air control (IAC) motor and throttle
position sensor (TPS).
(19) Verify that wire harness connector is firmly con­
nected to the engine coolant temperature sensor (Fig. 51).
Fig. 51 Engine Coolant Temperature Sensor—-8.0L Engine
(20) Raise and support the vehicle.
(21) On all 8.0L engines (HDC or MDC), verify
that the left and right oxygen sensor wire connectors
are firmly connected to the sensors. Inspect sensors
and connectors for damage (Fig. 52).
(22) On 8.0L MDC engine, verify that the pre-cat­
alyst and post catalyst oxygen sensor wire connectors
are firmly connected to the sensors. Inspect sensors
and connectors for damage (Fig. 53).
(23) Inspect for pinched or leaking fuel tubes.
Inspect for pinched, cracked or leaking fuel hoses.
(24) Inspect for exhaust system restrictions such
as pinched exhaust pipes, collapsed muffler or
plugged catalytic convertor.
(25) I f equipped with automatic transmission, ver­
ify that electrical harness is firmly connected to park/
Fig. 52 Left/Right Oxygen Sensors
POST CATALYST PRE-CATALYST
OXYGEN . OXYGEN
SENSOR = K SENSOR
8 0 5 d d 8 5 0
Fig. 53 Pre-Catalyst/Post Catalyst Oxygen Sensors
neutral switch. Refer to Automatic Transmission
section of Group 21.
(26) Verify that the electrical harness connector is
firmly connected to the vehicle speed sensor (Fig. 54).
(27) Verify that fuel pump/gauge sender unit wire
connector is firmly connected to harness connector.
(28) Inspect fuel hoses at fuel pump/gauge sender
unit for cracks or leaks.
(29) Inspect transmission torque convertor housing
(automatic transmission) or clutch housing (manual
transmission) for damage to timing ring on drive
plate/flywheel.
(30) Verify that battery cable and solenoid feed
wire connections to the starter solenoid are tight and
clean. Inspect for chaffed wires or wires rubbing up
against other components.
ASD AND FUEL P U i P RELAYS
The following operations/tests apply to these
relays only: Automatic Shutdown (ASD) and Fuel
Pump. For operations/tests on all other relays, refer to
the appropriate section of this service manual.