Alfa Romeo alfa 33 Workshop Manual page 125

Cold starting is difficult or
impossible (continue)
Excessive fuel consumption
Slow pickup especially when
in direct drive
Engine easily knocks, over-
heats or self-ignites
FUEL SYSTEM
Probable cause
Starting control valve, if any, is
sticky
Ignition and starting systems are out
of order
Carburation, ignition or compression
are defective, as also mentioned in
case of insufficient max speed
Air cleaner intake stopped in the warm
position
Twin carburetor goes into action too
early
Carburation, ignition or compression
are defective, as also mentioned in
case of insufficient max speed (pres-
ence of exhaust smoke is possible)
A c c e l e r a t i o n p u m p n o t .properly
adjusted or defective or pump circuit
of jet and valves is defective
Diffuser well is clogged or otherwise
defective
Carburation or ignition are defective,
as also mentioned in case of insuffi-
cient max speed
Octane rating of petrol used is too
low
Engine cooling system is defective
Excessive scaling of engine cylinders
Having also excluded any ignition
defect, engine compression will have
to be tested since there could be
leaks coming from piston rings,
valves or cylinder head gaskets
Engine compression is poor
04-25
Corrective action
Free valve movement so that it can
properly follow control cable
Overhaul ignition and
systems
Checking operations to be performed
same as previously mentioned
thermostat located into
Replace
cleaner air intake
CAUTION:
Special attention should be paid
when checking fuel consumption
since speed load, road type as well as
driving habits play an important part
in establishing actual running fuel
consumption
Adjust relevant controls
Checking operations to be performed
same as previously mentioned
Overhaul pump and relevant circuits
Carefully overhaul air jet, diffuser
and relevant well making sure that
all components are properly rated
Checking operations to be performed
same as previously mentioned
Replace petrol in tank with a kind
having a higher octane rating
Check radiator, relevant thermostat
or shutter, if any, since the latter
could be improperly adjusted
Proceed to scale the engine
Check engine compression by means
of suitable gauge screwed onto spark
plug holes; overhaul or replace any
defective engine parts
Check compression and, if necessary,
overhaul the engine
starting
May 1983