normal misfire on 2 and 3 cylinder after new engine install
09-27-2004, 04:25 PM
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normal misfire on 2 and 3 cylinder after new engine install I installed a 409 cast iron block engine in my 2002 camaro. I am trying to tune it but keep showing misfires on #2 and #3 cylinders. I edited the low rpm and idle misfire tables in ls1 edit (made all values 32000). The vehicle seems to run ok. I was told this misfire reading was normal and can be edited out. I am also running richer on one bank. Can this really be edited out, or should I be looking elsewhere? I already checked the spark plugs and the fuel injectors.
09-28-2004, 09:15 AM
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Random misfires are normal. Concentrated misfires
are not normal. Though big cam, small converter,
etc. can elevate the counts. I'd say look at the
misfire count "noise floor" (log all 8 misfire current
PIDs, look at the min/max/avg values in Excel, and
see what "normal" is for this motor and whether
#2 and #3 are more than (say) 50% higher than the
rest. If so I would keep chasing mechanical causes.
If it's only a matter of degree I would set the misfire
threshold to something comfortably above the norm
but not the 32000 or 32767 "go away, boy!" value.
Just so you get warned about anything turning worse.
are not normal. Though big cam, small converter,
etc. can elevate the counts. I'd say look at the
misfire count "noise floor" (log all 8 misfire current
PIDs, look at the min/max/avg values in Excel, and
see what "normal" is for this motor and whether
#2 and #3 are more than (say) 50% higher than the
rest. If so I would keep chasing mechanical causes.
If it's only a matter of degree I would set the misfire
threshold to something comfortably above the norm
but not the 32000 or 32767 "go away, boy!" value.
Just so you get warned about anything turning worse.
