Fiat 1998 Marea Weekend, Service Manual

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Engine
Marea- Marea Weekend
ft
Fuel system 99
range
10.
4F042PJ01
Table summarizing pollutant emission tolerance values
CO (%) HC (p.p.m.)
C0
2
(%)
Upstream of the catalyzer 0.4 - 1
«S 500 ^ 12
Downstream of the catalyzer *S 0,35 sS 90
^ 13
Checking exhaust concentration of CO and HC
The concentration of carbon monoxide (CO) and unburnt hydrocarbons (HC) at the exhaust is measured
by inserting a suitably calibrated tester probe at least 30 cm into the end of the exhaust pipe.
1. Check that the idle CO and HC concentration values are those recommended in the table.
2. If the HC value is outside of the recommended limit, whilst that measured previously upstream of the
catalyzer was correct, the engine parameters are correct and therefore the cause of the problem should
be sought in the decreased efficiency of the catalyzer.
ENGINE IDLE SPEED CHECK
If the engine idle speed does not correspond to the recommended value and the system is the self-
regulating type then no adjustment can be carried out. It is therefore necessary to check that the accel-
erator linkage is correctly adjusted and then the cause of the problem should be sought by carrying out a
complete fault diagnosis using the diagnostic equipment.
IGNITION ADVANCE CHECK
The diagnostic equipment must be used to check the ignition advance angles at the various speeds.
4 2
Print n° 506.763/14