How many misfires are acceptable?
12-02-2009, 08:22 PM
#1
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How many misfires are acceptable? Hey everyone,
Just went out for a short drive to scan misfires and found that I had a few. I was wondering how many misfires in a given drive are acceptable (if any), and what the cause could be if I am only getting 1-2 misfires in one cyl and any given time. Mods that matter in this case are:
* Cold Air Intake
* LT Headers
* Cat Back
* 25 lb flywheel (stock is 52lbs)
* Poly Motor/Trans Mounts
* NGK TR6 Plugs
* MSD Wires
* HSW Wet Shot Plate Kit
I guess the reason I was scanning the misfires is becasue I went to a dyno day on NOV 7 and sprayed on the dyno and the second time I sprayed the Nitrous solenoid failed and I got fuel only (let off the spray immediately).
The Flywheel/Clutch combo was also JUST installed so I was thinking maybe I should do a CASE relearn since the rotational mass has changed?
Hptuners Log and Config are in this post (since it won't let me post a config here):
http://www.hptuners.com/forum/showpo...91&postcount=1
Just went out for a short drive to scan misfires and found that I had a few. I was wondering how many misfires in a given drive are acceptable (if any), and what the cause could be if I am only getting 1-2 misfires in one cyl and any given time. Mods that matter in this case are:
* Cold Air Intake
* LT Headers
* Cat Back
* 25 lb flywheel (stock is 52lbs)
* Poly Motor/Trans Mounts
* NGK TR6 Plugs
* MSD Wires
* HSW Wet Shot Plate Kit
I guess the reason I was scanning the misfires is becasue I went to a dyno day on NOV 7 and sprayed on the dyno and the second time I sprayed the Nitrous solenoid failed and I got fuel only (let off the spray immediately).
The Flywheel/Clutch combo was also JUST installed so I was thinking maybe I should do a CASE relearn since the rotational mass has changed?
Hptuners Log and Config are in this post (since it won't let me post a config here):
http://www.hptuners.com/forum/showpo...91&postcount=1
12-03-2009, 08:18 AM
#2
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I try not to log misfires. It got me unnecessarily worried. I would get 30-40 misfires on a normal log. The majority were at idle and low Rpms. Of course being cammed it is going to do it. However, I have never seen any negative effect on the engines performance.
I used tuning software, and basically just log misfires over 2000 Rpm. I adjusted the Engine MIL to not light up on me.
Of course it is always best to check to make sure it is not a mechanical issue that might be causing you problems.
Hope you work it out.
..WeathermanShawn..
I used tuning software, and basically just log misfires over 2000 Rpm. I adjusted the Engine MIL to not light up on me.
Of course it is always best to check to make sure it is not a mechanical issue that might be causing you problems.
Hope you work it out.
..WeathermanShawn..
12-03-2009, 09:26 AM
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Thanks for the advice, I mean I'm only getting 1-2 counts at random times in random cyl. I think it might just be "normal" behavior, but I'm just looking for some more opinions!
12-03-2009, 02:12 PM
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A low level of misfiring is normal, so long as it's random.
Seeing them clumped in one cylinder or one bank, is
not.
A light flywheel is going to make for more crank ripple
and a higher false detection rate. My misfires went up
a lot when I went to a smaller diameter converter.
Seeing them clumped in one cylinder or one bank, is
not.
A light flywheel is going to make for more crank ripple
and a higher false detection rate. My misfires went up
a lot when I went to a smaller diameter converter.
12-03-2009, 02:17 PM
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A low level of misfiring is normal, so long as it's random.
Seeing them clumped in one cylinder or one bank, is
not.
A light flywheel is going to make for more crank ripple
and a higher false detection rate. My misfires went up
a lot when I went to a smaller diameter converter.
Seeing them clumped in one cylinder or one bank, is
not.
A light flywheel is going to make for more crank ripple
and a higher false detection rate. My misfires went up
a lot when I went to a smaller diameter converter.
