Ford COUGAR 1968 Shop Manual page 308

8-24 GROUP 8
-
-Engine
FIG. 47
(Continued)-Engine Diagnosis Guide
ROUGH ENGINE IDLE
POOR ACCELERATION
DELAYED DECELERATION
( COAST-DOW N)
Operate engine at idle speed and Fouled or improperly adjusted spark
normal operating temperature, and ob- plugs.
serve if engine idle is rough. Incorrect ignition timing.
High secondary wiring resistance.
F U E L SYSTEM
Secondary wiring connected wrong
or loose connections.
Leaking vacuum line connections,
hoses disconnected, or leaking caps.
EXHAUST SYSTEM
Engine idle speed set.too low.
Idle fuel mixture needle(s) not pro-
Exhaust control valve inoperative or
perly adjusted.
sticking (if so equipped).
Air leaks between the carburetor,
spacer, and the manifold and/or
ENGINE
fittings.
:
Intake manifold gasket leak (Vi8). : ~ e a k i n ~ vacuum line connections,
Power valve leaking fuel. hoses disconnected, or missing caps.
Idle fuel system air bleeds or fuel Leaking intake manifold gasket.
passages restricted. Loose engine mounting bolts or
Secondary throttle plates not closing
worn engine support insulator.
(4-V carburetor). Cylinder head bolts not properly
Float setting incorrect. torqued.
Hot and cold air intake system (air Crankcase ventilation regulator
cleaner) stuck in heat on position. valve defective or a restricted vent tube.
Valve clearance set too tight.
IGNITION SYSTEM Worn camshaft lobes.
Perform a manifold vacuum or
Improperly adjusted or defective compression test to determine which
breaker points. mechanical component is at fault.
Remove air cleaner; actuate acceler-
Accelerating pump malfunction.
ator linkage and check fuel discharge
Float setting incorrect.
into carburetor intake bore(s).
Leaky power valve, gasket or accel-
If accelerating pump action appears
erating pump diaphragm.
normal, ctieck'the ignition system, fuel
Power valve piston stuck in the up
system, brakes, transmission and en-
position (6-cylinder).
gine as follows:
Restricted fuel filter.
Defective fuel pump.
IGNITION SYSTEM
BRAKES
Incorrect .ignition timing.
Fouled or improperly adjusted spark Improper adjustment-too tight.
plugs.
Improperly adjusted or defective TRANSMISSION
breaker points.
Distributor not advancing properly.
Clutch slippage (manual-shift trans-
Improperly connected, leaking, or missions).
disconnected distributor vacuum lines. Improper band adjustment (automa-
tic transmissions).
F U E L SYSTEM
Converter One-way Clutch (auto-
matic transmissions).
Dirty air cleaner element, or defec-
tive hot-cold valve (air cleaner) override ENGINE
vacuum motor.
Throttle linkage not properly ad-
Perform a manifold vacuum or com-
justed. .
pression test to determine which me-
Accelerating pump stroke not pro-
chanical component of the engine is
perly adjusted. a t fault.
Operate engine and determine if de- Check anti-stall dashpot for specified
celeration rate is too slow. clearance.