trouble shoot my lean AFR problem
11-18-2008, 06:27 PM
#1
trouble shoot my lean AFR problem
I need a bit of help and some possbile insights as to what may be causing my AFR to go lean.
When I go WOT in 1st gear my afr gets real lean but 2nd gear is fine. Then if I drive normal thru 1st and matt it in 2nd it will go lean. I'm currently running the AP with an MM tuned map. The maps for 1st and 2nd gear are the same and I've tried 3rd and 4th but they are always fine so I dunno.
Here's what I know for now: MAF sensor clean, No CELs, No hesitation during WOT, No cat, New Mazsport ignition solution so coils should be good, New plugs, No hard starts, timing stays at a flat 30/15 diff during WOT
wada ya think
When I go WOT in 1st gear my afr gets real lean but 2nd gear is fine. Then if I drive normal thru 1st and matt it in 2nd it will go lean. I'm currently running the AP with an MM tuned map. The maps for 1st and 2nd gear are the same and I've tried 3rd and 4th but they are always fine so I dunno.
Here's what I know for now: MAF sensor clean, No CELs, No hesitation during WOT, No cat, New Mazsport ignition solution so coils should be good, New plugs, No hard starts, timing stays at a flat 30/15 diff during WOT
wada ya think
Last edited by Mr.&Mrs.Magic; 11-18-2008 at 06:32 PM.
11-18-2008, 07:01 PM
#4
old coils are shot! Shouldn't the ECU try and correct the problem in some way Because the only thing that changes to any noticable extent is afr.
this is what they looked like after a good thumb rubbin
this is what they looked like after a good thumb rubbin
Last edited by Mr.&Mrs.Magic; 11-18-2008 at 07:12 PM.
11-19-2008, 07:24 PM
#6
well thats good news about the coils but i pick up 20+hp(this is a guess went from mustang dyno at 134 to dynojet at 187) by switching to the mazsoprt ignition solution. I think you missed the part where I said this is not a base MM map. This is from a tune he sent me after I had established the proper MAF recal and sent him a datalog. If it was a maping issue shouldn't it show in both 1st and 2nd not just the first time I go WOT. Ither way I have gone back to 3a base map to see If I can reproduce the lean spikes
Last edited by Mr.&Mrs.Magic; 11-19-2008 at 07:40 PM.
11-20-2008, 12:22 PM
#8
Not sure exactly what you mean but I got the format to create the log from r0tor. https://www.rx8club.com/series-i-engine-tuning-forum-63/d-i-y-datalog-graph-your-ap-efi-dude-scanalyser-157648/ and I used ATR to get the datalog
11-20-2008, 12:36 PM
#9
There is no way that ignition timing curve is correct.
Your boosted ignition curve should drop down to 11 or so at the 4k range and work its way back up to 20 or so at most by redline. (Not exact numbers - just ranges).
Have you verified the accuracy of your AFR readings with an external AFR gauge?
I know that my OE sensor is significantly slower than my Innovate.
BTW - that pic of your OE coils is meaningless.
Brand new coils look like that after only a few days. Its just mineral migration from the environment and the interaction with the EMF from the coils.
Your boosted ignition curve should drop down to 11 or so at the 4k range and work its way back up to 20 or so at most by redline. (Not exact numbers - just ranges).
Have you verified the accuracy of your AFR readings with an external AFR gauge?
I know that my OE sensor is significantly slower than my Innovate.
BTW - that pic of your OE coils is meaningless.
Brand new coils look like that after only a few days. Its just mineral migration from the environment and the interaction with the EMF from the coils.
11-20-2008, 01:00 PM
#10
There is no way that ignition timing curve is correct.
Your boosted ignition curve should drop down to 11 or so at the 4k range and work its way back up to 20 or so at most by redline. (Not exact numbers - just ranges).
Have you verified the accuracy of your AFR readings with an external AFR gauge?
I know that my OE sensor is significantly slower than my Innovate.
BTW - that pic of your OE coils is meaningless.
Brand new coils look like that after only a few days. Its just mineral migration from the environment and the interaction with the EMF from the coils.
Your boosted ignition curve should drop down to 11 or so at the 4k range and work its way back up to 20 or so at most by redline. (Not exact numbers - just ranges).
Have you verified the accuracy of your AFR readings with an external AFR gauge?
I know that my OE sensor is significantly slower than my Innovate.
BTW - that pic of your OE coils is meaningless.
Brand new coils look like that after only a few days. Its just mineral migration from the environment and the interaction with the EMF from the coils.
By boosted do you mean FI because i'm NA or is this just more tunner lingo -->
I have been waiting till christmas for the AEM uego so the answer to that question is no.
Thought 1 way to tell how your coils are is by how white the the bottoms are again -->
11-20-2008, 01:34 PM
#12
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^Doesn't the stock tune stay at 30 leading 15 trailing for a fairly large high load RPM range?
Is this one of MM's flashes? How many times have you data-logged this behavior?
Is this one of MM's flashes? How many times have you data-logged this behavior?
11-20-2008, 01:47 PM
#13
I just switched to base 3a map a few days ago and was trying to see if I could get the spikes on a base map. Unfortunatly Johnny law heard my car and saw a huge fire ball come out so that pretty much stop my logging for the day(stupid turboxs pipe). Strangly he was pretty nice once I explained what I was doing and showed him the laptop plugged into the car.
11-20-2008, 02:55 PM
#14
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I'm surprised he didn't try to bust your chops about the emissions 
Have you tried logging with the stock tune to see if the same (or at least similar) behavior is there?
MM: Do you change the closed loop exit RPM in your flashes?
Have you tried logging with the stock tune to see if the same (or at least similar) behavior is there?
MM: Do you change the closed loop exit RPM in your flashes?
11-20-2008, 03:56 PM
#17
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If you're doing more data-logging, humor me and my craziness and log STFT as well. It may seem like an odd request, but it is an indicator of closed loop vs. open loop operation (it will always be 0 in open loop).
The only working theory I have is that when you get the lean spike you're still actually in closed loop operation... when you do a WOT run in 1st gear, you eventually get into open loop, and it remains in open loop through 2nd gear, and thus your 2nd gear graph looks good. When you "take it easy" in 1st gear, and do a WOT pull in 2nd gear almost the entire thing ends up being in closed loop and you see the lean spike again. It's a pretty "out there" theory, and it shouldn't happen unless MM tweaks some things that I really doubt he messes with, but it's all I can come up with at this point.
My only other suggestion would be to get a different/better wide-band as a second opinion on your AFR.
The only working theory I have is that when you get the lean spike you're still actually in closed loop operation... when you do a WOT run in 1st gear, you eventually get into open loop, and it remains in open loop through 2nd gear, and thus your 2nd gear graph looks good. When you "take it easy" in 1st gear, and do a WOT pull in 2nd gear almost the entire thing ends up being in closed loop and you see the lean spike again. It's a pretty "out there" theory, and it shouldn't happen unless MM tweaks some things that I really doubt he messes with, but it's all I can come up with at this point.
My only other suggestion would be to get a different/better wide-band as a second opinion on your AFR.
11-20-2008, 04:08 PM
#18
you may be on to something here. when I mat it the stft goes from negs to + then to 0 for the remainder. as soon as it goes open/0 stft wham lean spike. the highlighted area from left to right is AFR, MAF, MAF volt, STFT. Load also goes up a bit and then back to 100 or there about
Last edited by Mr.&Mrs.Magic; 11-20-2008 at 04:13 PM.
11-20-2008, 04:24 PM
#20
possible fuel pump issues? maybe the signal telling to pump to START FREAKING PUMPING is getting there to slow. how could I trace this as a possible solution.
Fuel pluse width doesn't seem to be much different when I compare the gear to load and rpm
Fuel pluse width doesn't seem to be much different when I compare the gear to load and rpm
Last edited by Mr.&Mrs.Magic; 11-20-2008 at 04:35 PM.
11-21-2008, 04:41 PM
#22
Ok so after switching back to the stock V1c_3a map from MM I've been trying to tell myself the car wasn't pulling any harder It's just my brain playing tricks on me and the fuel trims weren't settled yet. After a week of tooling around I tried to do a bit of logging yesterday and was very unsuccessful thanks to mr. law dog. So today I gave it another shot today and could not get a WOT run for first because the damn tires would cut loose big time. This was a big suprise to me as I have never had such trouble with spinng and frankly didn't think this car has to power to do such things . Any way long story short I got a 2nd and 3rd ger WOT pull and these are the graphs.
Looks like the afr is all over the place but the spikes are no longer in the danger zone and the upper RPM AFR rage it's far better than the stupid 11's I was getting. When I sent in for my first tune with jeff I had a gutted stock cat but have since switched to the full turboxs pipe maybe this was the problem. Any who I'm going to drive for another few days and relog everything and see what I come up with.
Oh and I also noticed the spikes are in roughly the same place 6500-7000 RPM'S
. Any way long story short I got a 2nd and 3rd ger WOT pull and these are the graphs. Looks like the afr is all over the place but the spikes are no longer in the danger zone and the upper RPM AFR rage it's far better than the stupid 11's I was getting. When I sent in for my first tune with jeff I had a gutted stock cat but have since switched to the full turboxs pipe maybe this was the problem. Any who I'm going to drive for another few days and relog everything and see what I come up with.
Oh and I also noticed the spikes are in roughly the same place 6500-7000 RPM'S