Dodge RAM TRUCK 1500 1995 Service Manual page 857

BR
ENGINES 9 -13
SERVICE DIAGNOSIS—DIESEL—PERFORMANCE—CONT.
CONDITION
POSSIBLE C A U S E S
ENGINE STARTS, BUT WILL
NOT KEEP RUNNING
1. Idle speed too low for the
accessories.
2. Intake air or exhaust system
restricted.
3. Air in the fuel system or the fuel
supply is inadequate.
4. Fuel waxing due to extremely
cold weather.
5. Contaminated fuel.
1 Adjust the idle speed.
2. Visually check for exhaust restriction a . .
inspect the air intake. Repair/replace
restricting parts.
3. Check flow through the filter and bleed
the system. Locate and eliminate the air
source.
4. Verify by inspecting the fuel filter. Clean
the system and use climatized fuel.
Replace fuel/water separator filter. Check
fuel heater for proper operation.
5. Verify by operating the engine with cle<
fuel from a temporary supply tank. Check
for presence of gasoline. Replace
fuel/water separator filter.
SURGING (SPEED
CHANGE)
1. If the condition occurs at idle,
• the idle speed is set too low for
the accessories.
2. Improperly operating injection
pump.
1. Adjust the idle speed.
2. Replace the injector pump.
ROUGH IDLE
(IRREGULARLY FIRING OR
ENGINE SHAKING)
1. If engine is cold, intake heater
system defective.
2. Idle speed too low for the
accessories.
3. Engine mounts damaged or
lose.
4. High pressure fuel leaks.
5. Air in the fuel system.
6. Sticking needle valve in an
injector.
1. Refer to intake heater system (see Group
14, Fuel System).
2. Adjust idle speed.
3. Repair or replace mounts.
4. Correct leaks in the high pressure lines,
fittings or delivery valves.
5. Bleed the fuel system and eliminate the
j
source of the air.
6. Check and replace the injector with the
sticking needle valve.
ENGINE RUNS ROUGH
1. Fuel injection lines leaking.
2. Air in the fuel or the fuel supply
is inadequate.
3. Contaminated fuel.
1. Correct leaks in the high pressure lines
fittings, injectors sealing washers or
delivery valves.
2. Check the flow through the filter and
bleed the system. Locate and eliminate
the air source.
3. Verify by operating the engine with clean
fuel from a temporary supply tank. Check
for presence of gasoline. Replace
fuel/water separator filter.
J9509-147