TEST NS-4AREPAIRING A START AND STALL CONDITION
Perform TEST NS-SEL Before Proceeding
At this point in the diagnostic test procedure it is assumed that all of the engine electrical systems
are operating as designed and are not the cause of a start and stall, or a no start problem. The
following additional items should be checked as possible mechanical problems. Any one of these
items can produce a start and stall, or no start condition; none can be overlooked as a possible
cause.
1. ENGINE VALVE TIMINGÐ must be within specifications
2. ENGINE COMPRESSIONÐ must be within specifications
3. ENGINE EXHAUST SYSTEMÐ must be free of any restrictions
4. FUELÐ must be free of contamination
5. FUEL FILTERÐ must be free of any restrictions
6. INTAKE AIR DUCTÐ passages must be free of any debris
Always look for any Technical Service Bulletins that may relate to this problem.
N
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11.0 REQUIRED TOOLS AND EQUIPMENT
ammeter
DRB (diagnostic read-out box) scan tool
jumper wires and probes
ohmmeter
vacuum gauge
voltmeter
12.0 GLOSSARY OF TERMS
backfire,
popbackfuel ignites in either the intake or the exhaust system
BCMbody control module
cuts out,
missesa steady pulsation or the inability of the engine to maintain a consistent
rpm
DLCdata link connector (previously called ``engine diagnostic connector'')
detonation,
pre-ignitiona mild to severe ping, especially under loaded engine conditions
ECMengine control module
ECTengine coolant temperature sensor
EGRexhaust gas recirculation valve and system
generatorpreviously called ``alternator''
hard startThe engine takes longer than usual to start, even though it is able to
crank normally.
hesitation,
sag, stumbleThere is a momentary lack of response when the throttle is opened.
This can occur at all vehicle speeds. If it is severe enough, the engine
may stall.
IATintake air temperature sensor
lack of power,
sluggishThe engine has less than expected power, with little or no increase in
vehicle speed when the throttle is opened.
MILmalfunction indicator lamp
PDCpower distribution center
poor fuel
economyThere is significantly less fuel mileage than other vehicles of the same
design and configuration.
G
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