Misfire CEL
#16
The first tuner was Chris black from ams. The next tuner is a guy named Seth who from a good friend of mine recommended to have look. I won't be using the injectors for this tune because it's last minute and I tune on Saturday so he might see something I can't
#20
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iTrader: (4)
Join Date: Aug 2008
Location: Livermore
Posts: 2,127
Car Info: LUMPY CGM 05 WRX
You are on a hybrid, and my understanding is it is tuned by AMS.
You are now getting tuned again by another guy named seth.
Did you add anything between tunes?
How much data do you have on the hybrid? Did you have it build or buy it that way?
What head gasket was used when the build was done? You may have a higher comp ratio.
Trying to help but need lots of data, also I AM NO WHERE NEAR ANYTHING RESEMBLING AN EXPERT.
I am just asking questions that may help one of the reputable shops in the area that paruse our threads get some data.
#23
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iTrader: (4)
Join Date: Aug 2008
Location: Livermore
Posts: 2,127
Car Info: LUMPY CGM 05 WRX
I am going to re visit what I said earlier.
Just going from what I have read and learned.
from what I understand of hybrids they are prone to detonation there are two reasons for this.
#1 Without the proper head gasket the 2.0 ltr head has a smaller combustion chamber which raises the compression ratio. One way to mitigate this is to use a thicker head gasket which is what I did when mine was built. Without the thicker head gasket it will run a higher compression ratio which if not tuned for will cause detonation.
#2 The combustion chamber does not match the bore size leaving a small lip at the top of the cylinder. This lip can have a tendancy to hold heat and "HOT SPOT" there by igniting the fuel before it is supposed to.
if #1 is the case it will cause #2 to happen more often.
At least this is what I have read on the interwebs, and we all know if its on the interwebs it must be true.
The above is not a game ender it can be tuned for, and I am not a tuner but I think to tune it out it goes somthing like more fuel, less boost, and less timing. when you add those three together it usually = less power.
Just going from what I have read and learned.
from what I understand of hybrids they are prone to detonation there are two reasons for this.
#1 Without the proper head gasket the 2.0 ltr head has a smaller combustion chamber which raises the compression ratio. One way to mitigate this is to use a thicker head gasket which is what I did when mine was built. Without the thicker head gasket it will run a higher compression ratio which if not tuned for will cause detonation.
#2 The combustion chamber does not match the bore size leaving a small lip at the top of the cylinder. This lip can have a tendancy to hold heat and "HOT SPOT" there by igniting the fuel before it is supposed to.
if #1 is the case it will cause #2 to happen more often.
At least this is what I have read on the interwebs, and we all know if its on the interwebs it must be true.
The above is not a game ender it can be tuned for, and I am not a tuner but I think to tune it out it goes somthing like more fuel, less boost, and less timing. when you add those three together it usually = less power.
#26
Registered User
iTrader: (9)
checked end of coil (connection between coil and plug) for any corrosion? seems with low RPMS and low/slow spark count, its having a hard time making that jump onto plug. on my way down to subiefest this year, i had a jank number 1 plug wire (RS) that wasnt making the connection at low rpms but ran smooth on freeway. would misfire like crazy on city streets. another probable cause could be clogged and/or dirty injectors. GL bud!
#27
I have newer injectors to put in but they are bigger so they require a tune for them. Hopefully I can eliminate that with the new ones. I read any bad differentials can cause misfire due to binding in them. I sure hope it's not that.
#29
Some one on nasioc had a center diff issue which was causing his misfire. So ya never know lol either way the car doesn't seem to even really misfire. I might change front o2 sensor I get bank 1 low codes every so often
#30
Registered User
iTrader: (9)
+1. i also suggest buying the torque app and dongle if you have not already so. having live data helps a lot when diagnosing. youll be able to tell if your front O2 is indeed failing before spending cash and replacing parts. test voltage with DVOM or torque different systems. ignition, fuel deliv, charging, etc. GL!