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99 silverado Misfires

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  #1  
Old 08-09-2009, 11:44 PM
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Default 99 silverado Misfires

I have replaced all the plugs with performance plugs and ran fuel injector cleaner through it. Any ideas what could be next? My thoughts are banking on a bad injector, or possibly bad plugwire or coil? I have also heard of a "Knock sensor" which another guy I know of was having problems with, as his plug in one cylinder would be burnt to a crisp within a week of replacement. One thing I did do was run STP Octane through the motor as it said on the label "Reduces engine knock" and it did seem to run alot more smooth.
 
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Old 08-10-2009, 10:28 AM
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Is it a knock or a clatter? Need more information...
 
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Old 08-10-2009, 02:36 PM
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how about the crank sensor......does it do it when the engine is cold?
 
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Old 08-10-2009, 09:56 PM
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It does it when Its cold. Im thinkin knock, it doesnt resemble a clattering noise. Im new. So, well, yeah.
 
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Old 08-10-2009, 11:42 PM
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its probably the crank sensor
 
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Old 08-11-2009, 07:36 AM
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I would start with the new plug wires and if that doesn't fix it get a compression check on all the cylinders done and a fuel pressure check. Does the miss go away when you give it gas?
 
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Old 08-11-2009, 02:44 PM
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Yeah once I give it gas its low range is sluggish, but it kicks in well at mid range.
 
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Old 08-11-2009, 08:06 PM
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Then I would definitely do what I suggested above.
 
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