1999 GMC Suburban misfire cyl. 2

1999 GMC SUBURBAN
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DANIELSON
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Engine Performance problem
1999 GMC Suburban V8 Four Wheel Drive Automatic 300k miles

code reader says cyl 2 missfire,changed plugswires,cap,rotor[not coil] 1st time on engine.
compression good on all 7 [120 lbs] but number 2 is198 lbs.[carbon build up? if so why only on 1 cyl?]
if u step on it runs on all 8, if no load on engine runs on 7.

thank you Dan
Nov 12, 2009 at 8:37 PM
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RASMATAZ
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Carbon build up will raise the compression in your case no.2 also check the injector for the that cylinder

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.
Nov 12, 2009 at 8:41 PM
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DANIELSON
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thank you
Dan
Nov 12, 2009 at 9:05 PM
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