diagnostic

1996 GMC SIERRA
V8 • 4WD • AUTOMATIC
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TTANYA1997
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  • 1 POST
what does a diagnostic test result of "fuel to rich" mean? how do we fix the problem? we've changed plugs, wires, distributor but the truck still runs rough and misses while idling.
Mar 6, 2011 at 9:50 PM
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RASMATAZ
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Probable causes of an engine running rich are as follows:

1.Excessive fuel pressure can be cause by restricted fuel return line
2.Defective Oxygen Sensors.
3.Leaking injectors and fuel pressure regulator.
4.Coolant temperature sensor out of calibration.
5.Restricted air intake system.
Mar 6, 2011 at 9:51 PM
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