Page 33 of 39
The complexity of the diesel engine makes it so the owner is discouraged
from attempting to perform maintenance other than the services
described in this supplement.
If you experience difficult starting, rough idling, excessive exhaust
smoke, a decrease in engine performance or excess fuel consumption,
perform the following checks:
²a plugged air inlet system.
²water in the fuel filter/water separator.
²a clogged fuel filter.
²contaminated fuel.
²air in the fuel system, due to loose connections.
²an open or pinched sensor hose.
²low engine oil level.
If these checks do not help you correct the engine performance problem
you are experiencing, consult an authorized dealer.
FUELING
Do not use starting fluid such as ether or gasoline in the diesel
air intake system. Such fluids can cause immediate explosive
damage to the engine and possible personal injury.
If you fuel your vehicle at a truck stop, you may notice that the fuel
nozzle may shut off every 5±10 seconds. This is due to the flow rates
being designed for larger heavy duty trucks. You may have to fuel at a
slower rate (don't depress the nozzle trigger fully).
Do not run your diesel vehicle out of fuel as this will allow air to enter
the fuel system which will make restarting difficult. Longer engine
cranking time may be required once air is in the fuel system. If air enters
the fuel system (either through running the fuel tank(s) empty or during
a fuel filter change), the engine will self-purge the trapped air once it
starts running. The engine may run roughly and produce white smoke
while air is in the fuel system; this is normal and should stop after a
short time.
Minor troubleshooting guide
33
Page 34 of 39
IF THE ENGINE WON'T CRANK
Turn on the headlights. If the lights are dim, do not go on at all or if
when the ignition is turned to START the lights become dim or go out,
the battery connections may be loose or corroded, or the battery may be
discharged. If there is a clicking or stuttering sound coming from the
engine compartment when you turn the key to START, this may also
indicate a loose or corroded battery connection.
Check the battery connections at the battery posts, cable connection to
the engine grounding point and at the starter relay terminals. Also, make
sure the relay bracket is securely fastened to its mounting surface.
If the starter relay clicks, but the starter does not crank, check the
connections at the starter terminal. If a discharged battery is suspected,
have it checked and corrected.
²For vehicles with manual transmissions, the clutch pedalmustbe fully
depressed in order for the starter to operate.
²For vehicles with automatic transmissions, the gearshift lever must be
in Park or Neutral in order for the starter to operate.
²Try operating the starter switch several times. Should the switch be
corroded, this operation may clean the contacts or make the switch
temporarily operable until you can reach the dealer.
²If all electrical connections are tight and you need assistance to start,
see ªJump Starting Your Vehicleº in theStartingchapter.
IF ENGINE CRANKS BUT WON'T START
Prolonged starter cranking (in excess of 30 seconds) could cause
damage to the starter motor.
²Check the fuel gauge. You may be out of fuel. If the gauge shows that
there is fuel in the tank, the trouble may be in the electrical system or
the fuel system. If equipped with an auxiliary tank, be sure that the
tank control switch is set for the tank with fuel and not on an empty
tank.
²Leaving the ignition key ON for over two minutes without starting may
make starting difficult because the glow plugs will cease activation.
Reset the system by turning the ignition key to OFF and then back to
ON again.
Minor troubleshooting guide
34
Page 35 of 39
IF THE ENGINE RUNS HOT
The following could cause the engine to overheat:
²Lack of coolant.
²Dirty cooling system.
²Driving with frozen coolant.
²Sticking thermostat.
²Overloading or pulling heavy trailers during hot weather.
²Grill or radiator air blockage.
²Slipping or missing drive belt.
²Plugged or very dirty air cleaner element.
IF FUSES BURN OUT
Burned-out or blown fuses usually indicate an electrical short-circuit,
although a fuse may occasionally burn out from vibration. Insert a second
fuse. If this fuse immediately burns out and you cannot locate the cause,
return your vehicle to your dealer for a circuit check.
Replacement fuses and circuit breakers must always be the same
rating as the original equipment shown. Never replace a fuse or
circuit breaker with one of a higher rating. Higher rated fuses or circuit
breakers could allow circuit overloading in the event of a circuit
malfunction, resulting in severe vehicle damage or personal injury.
Refer to the ªOwner Guideº for replacement of fuses.
Minor troubleshooting guide
35