VQ35de uneven bank AFR (Evidence inside!)
12-01-2010, 09:08 PM
#42
01-26-2011, 07:58 AM
#48
THE **** MISFIRE IS GONE!!!!! (sorry for caps, im screaming lol)
So I was driving on the highway, didnt have any intentions to floor it or anything was just chilling (it was a 40min drive), so I descided, you know what! let me just do it, I went WOT and didnt feel a SINGLE hicup, nothing! I havent felt a smooth 3rd gear pull since almost a year ago lol. I couldnt believe it, so I pulled out the laptop and logged another run, everything has perfectly straight curves, timing, afr, inj, maf input. Was freaking awesome! Was actually mad at first lol, i was like "wtf your supposed to be misfiring damit!!".
Now, possible solutions, i have no idea. Recently adjusted my TPS (i have always had it on the high side of specs so i brought it down a lil bit, also plugged in the IAT sensor and have it laying in the engine bay (before wasnt plugged at all). Thats pretty much it, oh and AFR are in the high 11 low 12, so perfect.
So I was driving on the highway, didnt have any intentions to floor it or anything was just chilling (it was a 40min drive), so I descided, you know what! let me just do it, I went WOT and didnt feel a SINGLE hicup, nothing! I havent felt a smooth 3rd gear pull since almost a year ago lol. I couldnt believe it, so I pulled out the laptop and logged another run, everything has perfectly straight curves, timing, afr, inj, maf input. Was freaking awesome! Was actually mad at first lol, i was like "wtf your supposed to be misfiring damit!!".
Now, possible solutions, i have no idea. Recently adjusted my TPS (i have always had it on the high side of specs so i brought it down a lil bit, also plugged in the IAT sensor and have it laying in the engine bay (before wasnt plugged at all). Thats pretty much it, oh and AFR are in the high 11 low 12, so perfect.
01-26-2011, 01:26 PM
#49
Good news streetz!
Question, are you still using the converted e-tb? Or did you end up going with the pathfinder unit?
Also, If im not mistaken, running with the IAT unplugged causes the ECU to pull timing similar to not having the KS plugged in at all. I've been meaning to log this to confirm 100% though. Could too much timing being pulled cause misfires in an application such as yours where alot of fuel (compared to stock) needs to be burned off?
Question, are you still using the converted e-tb? Or did you end up going with the pathfinder unit?
Also, If im not mistaken, running with the IAT unplugged causes the ECU to pull timing similar to not having the KS plugged in at all. I've been meaning to log this to confirm 100% though. Could too much timing being pulled cause misfires in an application such as yours where alot of fuel (compared to stock) needs to be burned off?
01-26-2011, 01:32 PM
#50
Good news streetz!
Question, are you still using the converted e-tb? Or did you end up going with the pathfinder unit?
Also, If im not mistaken, running with the IAT unplugged causes the ECU to pull timing similar to not having the KS plugged in at all. I've been meaning to log this to confirm 100% though. Could too much timing being pulled cause misfires in an application such as yours where alot of fuel (compared to stock) needs to be burned off?
Question, are you still using the converted e-tb? Or did you end up going with the pathfinder unit?
Also, If im not mistaken, running with the IAT unplugged causes the ECU to pull timing similar to not having the KS plugged in at all. I've been meaning to log this to confirm 100% though. Could too much timing being pulled cause misfires in an application such as yours where alot of fuel (compared to stock) needs to be burned off?
01-26-2011, 04:01 PM
#52
lol why you gotta be negative lol. Most likely I will dyno before going to the track, this semester is tough and busy so I wont be dedicating much time to the car except small things here and there, maybe random vid's or something. And now I have a long commute for an internship so I cant risk messing it up lol although I should be putting up the boost back to high teen's again soon.
I have also changed the mixture of my injection, I am now using more water than meth, probably like 70/30, reason being is that I believe my setup develops too much heat due to the 2" piping (I could be wrong), so the added water will take care of that, usually the rule of thumb is if your IC piping setup is not efficient then more water is needed, if IC piping setup is very efficient then very little to no water would be needed (this is based on mad research i have done over the years lol)
I have also changed the mixture of my injection, I am now using more water than meth, probably like 70/30, reason being is that I believe my setup develops too much heat due to the 2" piping (I could be wrong), so the added water will take care of that, usually the rule of thumb is if your IC piping setup is not efficient then more water is needed, if IC piping setup is very efficient then very little to no water would be needed (this is based on mad research i have done over the years lol)
Last edited by streetzlegend; 01-26-2011 at 04:09 PM.
01-26-2011, 06:57 PM
#53
lol why you gotta be negative lol. Most likely I will dyno before going to the track, this semester is tough and busy so I wont be dedicating much time to the car except small things here and there, maybe random vid's or something. And now I have a long commute for an internship so I cant risk messing it up lol although I should be putting up the boost back to high teen's again soon.
I have also changed the mixture of my injection, I am now using more water than meth, probably like 70/30, reason being is that I believe my setup develops too much heat due to the 2" piping (I could be wrong), so the added water will take care of that, usually the rule of thumb is if your IC piping setup is not efficient then more water is needed, if IC piping setup is very efficient then very little to no water would be needed (this is based on mad research i have done over the years lol)
I have also changed the mixture of my injection, I am now using more water than meth, probably like 70/30, reason being is that I believe my setup develops too much heat due to the 2" piping (I could be wrong), so the added water will take care of that, usually the rule of thumb is if your IC piping setup is not efficient then more water is needed, if IC piping setup is very efficient then very little to no water would be needed (this is based on mad research i have done over the years lol)
good luck, high teen 20psi sound like a nice round #
Last edited by t6378tp; 01-26-2011 at 07:02 PM.
01-28-2011, 08:08 PM
#54
17psi TUNED!, MAF voltage at 8psi was 4.50s, at 17psi voltage was about 4.90, looks like im getting close to maxing out the Z32 maf 
also output duty cycle is on average at 73% with fuel pressure im assuming at 60psi.
also output duty cycle is on average at 73% with fuel pressure im assuming at 60psi.
Last edited by streetzlegend; 01-28-2011 at 08:10 PM.
01-23-2012, 05:23 AM
#58
So... the mystery remains. Now that I have a Z33 manifold (mrev2), I still have uneven bank AFR's. Not considering this a big deal but just some facts I wanted to put on this thread so it does not mislead peeps.
01-23-2012, 08:10 AM
#59
^^^ Hmm strange. I am running a similar set-up and my a/f between banks is pretty much dead even. This is using the Z33 manifold and a spacer.
SurraTT also has about a 0.5 variation between banks though with his 7th gen vq35.
SurraTT also has about a 0.5 variation between banks though with his 7th gen vq35.
01-23-2012, 11:57 AM
#61
11-03-2014, 06:58 AM
#62
Updating for documentation.
New discovery, it turns out that in my front bank, all exhaust valves leak. Rear bank, NO exhaust valves leak. This clearly shows why there was a difference in AFR.
Also the rear bank looks way more worn than the front, the pistons in the front look almost new with just a haze of bronze over them while the rear have black/carbon on them, so you can tell that the rear bank was producing more power, hence the higher compression.
The cause of this is still a mystery but once I put it back together with fresh rings and valves fix. I will tune both banks individually from day one.
New discovery, it turns out that in my front bank, all exhaust valves leak. Rear bank, NO exhaust valves leak. This clearly shows why there was a difference in AFR.
Also the rear bank looks way more worn than the front, the pistons in the front look almost new with just a haze of bronze over them while the rear have black/carbon on them, so you can tell that the rear bank was producing more power, hence the higher compression.
The cause of this is still a mystery but once I put it back together with fresh rings and valves fix. I will tune both banks individually from day one.
11-07-2014, 10:19 AM
#64
11-07-2014, 03:55 PM
#65
Updating for documentation.
New discovery, it turns out that in my front bank, all exhaust valves leak. Rear bank, NO exhaust valves leak. This clearly shows why there was a difference in AFR.
Also the rear bank looks way more worn than the front, the pistons in the front look almost new with just a haze of bronze over them while the rear have black/carbon on them, so you can tell that the rear bank was producing more power, hence the higher compression.
The cause of this is still a mystery but once I put it back together with fresh rings and valves fix. I will tune both banks individually from day one.
New discovery, it turns out that in my front bank, all exhaust valves leak. Rear bank, NO exhaust valves leak. This clearly shows why there was a difference in AFR.
Also the rear bank looks way more worn than the front, the pistons in the front look almost new with just a haze of bronze over them while the rear have black/carbon on them, so you can tell that the rear bank was producing more power, hence the higher compression.
The cause of this is still a mystery but once I put it back together with fresh rings and valves fix. I will tune both banks individually from day one.
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