Fiat 999 CC Automobile User Manual


 
Engine cuts out suddenly –
ignition fault
Loose or disconnected LT wires
Wet HT leads or distributor cap (after
traversing water splash)
Coil failure (check for spark)
Other ignition fault (see Chapter 4)
Engine misfires before cutting out
– fuel fault
Fuel tank empty
Fuel pump defective or filter blocked
(check for delivery)
Fuel tank filler vent blocked (suction will be
evident on releasing cap)
Carburettor needle valve sticking
Carburettor jets blocked (fuel contami-
nated)
Other fuel system fault (see Chapter 3)
Engine cuts out – other causes
Serious overheating
Major mechanical failure (eg camshaft
drive)
Ignition (no-charge) warning light
illuminated
Slack or broken drivebelt — retension or
renew (Chapter 9)
Ignition warning light not
illuminated
Coolant loss due to internal or external
leakage (see Chapter 2)
Thermostat defective
Low oil level
Brakes binding
Radiator clogged externally or internally
Electric cooling fan not operating correctly
Engine waterways clogged
Ignition timing incorrect or automatic
advance malfunctioning
Mixture too weak
Note: Do not add cold water to an overheated
engine or damage may result
Note: Low oil pressure in a high-mileage
engine at tickover is not necessarily a cause
for concern. Sudden pressure loss at speed is
far more significant. In any event check the
gauge or warning light sender before
condemning the engine.
Gauge reads low or warning light
illuminated with engine running
Oil level low or incorrect grade
Defective gauge or sender unit
Wire to sender unit earthed
Engine overheating
Oil filter clogged or bypass valve defective
Oil pressure relief valve defective
Oil pick-up strainer clogged
Oil pump worn or mountings loose
Worn main or big-end bearings
Pre-ignition (pinking) on
acceleration
Incorrect grade of fuel
Ignition timing incorrect
Distributor faulty or worn
Worn or maladjusted carburettor
Excessive carbon build-up in engine
Whistling or wheezing noises
Leaking vacuum hose
Leaking carburettor or manifold gasket
Blowing head gasket
Tapping or rattling
Incorrect valve clearances (where appli-
cable)
Worn valve gear
Worn timing chain or belt
Broken piston ring (ticking noise)
Knocking or thumping
Unintentional mechanical contact (eg fan
blades)
Worn drivebelt
Peripheral component fault (generator,
water pump, etc)
Worn big-end bearings (regular heavy
knocking, perhaps less under load)
Worn main bearings (rumbling and
knocking, perhaps worsening under load)
Piston slap (most noticeable when cold)
Engine noises
Low engine oil pressure
Engine overheatsEngine cuts out and will not restart
Fault Finding REF•11
REF
Crank engine and check for spark. Note
use of insulated tool