Hi guys. Car is generally running very well (Z32 TT, auto to man conversion). I've made quite a few mods and deletions, probably most significant for this issue is a Doolz intake and Selin Dual MAF translator and running 1.4 bar max although the problem occurs at much lower boost, even as low as 0.7 bar. I've just installed 2 x LC-1 widebands and 2 gauges so I can keep an eye on things the whole time, this has immediately highlighted a lean spot at low-mid revs under high load - enough to cause some det and make me back off the throttle. My confusion comes because the car is otherwise running fine and showing stoich where it should, booting it gives AFRs of around 14:1 though. My fuel map should be giving around 11.9:1 as I understand it.
Does this sound like a simple scaling problem? Perhaps TTP Max is too low (used the auto scaling with injector resizing)
I did some logging today but haven't had time to analyse it yet, anything I should be particularly concentrating on??
I know this is a bit vague at present but I don't want to waste too much time looking in the wrong place!
Cheers
RobH
Lean spot, not sure why?
Moderator: Matt
Re: Lean spot, not sure why?
Yeah really need a log and copy of the BIN file
However is it running 14.7:1 when you have the O2 sensors disabled / disconnected? It could be running O2 feedback upto the point when you push it out of closed loop (just a thought)
Once O2 feedback is disabled... see if it looks the same afterwards. If the problem is only in one area of the fuel map and assuming MAF readings are correct, have you tried adjusting your fuel map around the area where its running lean and richened it up a bit?
TTPmax will normally get 'maxed' out on automatic settings
Check with your TP scalings that maximum TP reached during a power run is about the same number in the RHS TP column on your fuel and timing maps
However is it running 14.7:1 when you have the O2 sensors disabled / disconnected? It could be running O2 feedback upto the point when you push it out of closed loop (just a thought)
Once O2 feedback is disabled... see if it looks the same afterwards. If the problem is only in one area of the fuel map and assuming MAF readings are correct, have you tried adjusting your fuel map around the area where its running lean and richened it up a bit?
TTPmax will normally get 'maxed' out on automatic settings
Check with your TP scalings that maximum TP reached during a power run is about the same number in the RHS TP column on your fuel and timing maps
Re: Lean spot, not sure why?
Thanks Matt.
Having read some similar posts I have my suspicions that the O2 flags are something to do with it, O2 sensors have been unplugged until recently, seems to run better at all engine speeds without them. I suspect one of them is stuffed anyway.
I had set the load scales really quite high, I was reaching figures of over 100 and set the max load value to around 125 for both timing and fuel, this put me in the last two columns under max load. Having looked at the logs it seems the max I've recently been hitting is below 70, I need to study it more carefully but I think this is keeping me around the middle of the map and in the lean AFR's (probably even in the O2 flagged area). Would this sound logical after going from using a single MAF sensor with a dual intake to a dual MAF and selin translator in ADD mode? (i.e. approximating the voltage of a single MAF) That's the only thing I can think of that's changed other than smoothing a boost spike out with an AVC-r.
The only other reason I can think that I'm not hitting anything like the load I was hitting previously is that I'm simply backing off the throttle due to the det, I'm only hitting low boost before det starts.
I think I need to start again. I'm happy with K value and latency so at least part of the work is done. I think the tune and maps have got into a bit of a mess due partly to vehicle configuration changes in the last year or so and partly because I'm learning as I go (I haven't got a clue what I'm doing
). I have no more config changes to make to the vehicle so the only thing missing is the final tune.
I'd like to ensure that I'm using the correct base image and start again, do you keep a record of which image was flashed onto which board Matt or can I identify this from the Nistune software?
Thanks in advance for any help, I'll get some logs and bins etc done once I'm happy I have a solid basic tune to start from.
Cheers
RobH
Having read some similar posts I have my suspicions that the O2 flags are something to do with it, O2 sensors have been unplugged until recently, seems to run better at all engine speeds without them. I suspect one of them is stuffed anyway.
I had set the load scales really quite high, I was reaching figures of over 100 and set the max load value to around 125 for both timing and fuel, this put me in the last two columns under max load. Having looked at the logs it seems the max I've recently been hitting is below 70, I need to study it more carefully but I think this is keeping me around the middle of the map and in the lean AFR's (probably even in the O2 flagged area). Would this sound logical after going from using a single MAF sensor with a dual intake to a dual MAF and selin translator in ADD mode? (i.e. approximating the voltage of a single MAF) That's the only thing I can think of that's changed other than smoothing a boost spike out with an AVC-r.
The only other reason I can think that I'm not hitting anything like the load I was hitting previously is that I'm simply backing off the throttle due to the det, I'm only hitting low boost before det starts.
I think I need to start again. I'm happy with K value and latency so at least part of the work is done. I think the tune and maps have got into a bit of a mess due partly to vehicle configuration changes in the last year or so and partly because I'm learning as I go (I haven't got a clue what I'm doing
). I have no more config changes to make to the vehicle so the only thing missing is the final tune.I'd like to ensure that I'm using the correct base image and start again, do you keep a record of which image was flashed onto which board Matt or can I identify this from the Nistune software?
Thanks in advance for any help, I'll get some logs and bins etc done once I'm happy I have a solid basic tune to start from.
Cheers
RobH