Jump to content
SAU Community

Safcii Rewired = Idle Leaning Out To Full

dm11

By dm11,
in General Maintenance

 Share

Recommended Posts

dm11 Newbie

dm11

Posted
Posted

R32 GTS-t Type M. So RB20DET in question. Bought the car 4 years ago, no mods aside from HKS SQV, AEM UEGO Wideband and SAFC II (all signal read fine, but adjustments would never affect the AFR) when bought.

At bottom there is a TL;DR, as this is very long ;)

So no with more money and time, I'm looking to finally do some actual modding to the car, not to mention lean out the rich(~14) idle a bit :P. Other than that, car ran like a beaut, perfect AFRs on boost, rich on idle and cruise though. Reason probably being that the O2 (disconnected by previous owner, as they put AEM Wideband in original O2 bung, and didn't route NB signal to ECU, reading constant voltage of 0.31 (lean).

As mentioned, I had a look at the ECU and wiring etc... SAFC II was wired mostly right, except 1 cable. The AFM signal read cable they simply spliced into the MAF sensor, and original MAF sensor cable was still directly connected to the ECU. One very odd thing I found, was the MAF ground cable coming from the ECU was cut. Turns out they connected the SAFC modified AFM signal cable to the MAF ground. I was surprised the car even worked in this configuration. Anyways, I simply cut the MAF wire right after the SAFC II splices into it. Then I took the modified AFM signal coming from SAFC and spliced it with the other part of the MAF cable going into the ECU as it should've originally been, and obviously reconnected the MAF ground wire to the ECU MAF ground pinout. (Let me know if I possibly messed up somewhere along here).

Reconnect battery, start engine up, runs beautifully first 10 seconds, right at stoich. Adjustments to the SAFC are making significant AFR differences even at idle. But then it keeps consistently leaning out idle, and after about a minute it leans out the idle to over 18, until it finally shuts downs. Only way to keep it alive was to fool ECU into thinking 24% more air is coming in through SAFC, in idle.

Anyways, I think the simple fix would be just to connect my WB to give a NB signal to ECU, so I end up doing that, reconnect etc... Again, at cold start up, keeps beautiful stoich idle, and then after a bit, RPMs start dropping, leaning out like crazy. I brought base RPM all the way to 900 RPM. Running the AEM in P04 mode just to confirm, ran it in P03 to see if I have a different model, but that's definitely wrong signal.

I hooked up my consult, to check voltages. Again, only way to keep the car from stalling out or sputtering like a mofo at idle, is by increasing fuel injector duty using consult or +30% adjustment on SAFC. It turns out the voltage for O2 sensor in P04 mode is going over 1v, seen it hit all the way to 1.4v, should be 0-1v, so for some reason it's adding that 0.31V and whatever else, to the NB input my AEM is giving. Anyone know what the fix for this is? When I disconnect my AEM, it goes to the stale 0.31V again, and all that really does is require a bit less adjustment from my SAFC to keep the car running. The real problem seems to be the MAF signal coming from SAFC. For input at idle, it's showing 1.1V(direct MAF voltage) which is good I believe (2000 rpm = 1.8V good according to manual). However, for the modified voltage coming from SAFC, it's 1.02-1.04 base adjustment is 0%. So there's a discrepancy in signals, the SAFC is returning a lower air value than is actually coming from MAF sensor :S, bad wiring???

I'm think it's these voltage issues causing the idle to be ****, so I'm wondering if anyone has suggestions on how to fix these, grounds bad or what??? Since I've had the car, tach would always go crazy and barely ever shows anything correct, the RPM signal from ECU, showing in SAFC and consult is perfect, so maybe bad grounds???

I don't think it's AAC or any of those, one reason being, the car worked fine before the rewire, and I'm sure if I rewire back to the MAF cable going directly to ECU, it'll work fine again. But I want the ability to change A/F signal for fine tuning ofc. However, all suggestions are welcome, at the current moment the car is undriveable if I set the 800 rpm adjustment to +30%, as it will go pig rich when trying to get into first gear.

List of mods

AEM WB

SAFCII

HKS SQV (not SSQV) http://www.upgarage....122001802s0.jpg

3A Pod filter

SAFC II settings

6 cylinder, rising

Sens. Cal 1:1

Attempted HW 1:1 / 4:4 / 2:5 all returned with lean idling conditions

HW 2:6 caused super rich idle condition, again starts stoich, moves down to 10.0 rich.

Should I be using HW?? I read someone used Flap and that fixed it for them?!?!

Sorry for the really long-ass post, but I'm trying to give you as much info as possible.

For TL;DR

******************

Rewired SAFC II to correct specifications according to manual, settings correct as far as manual concerned. Car ran perfectly before while it was only monitoring MAF signal. Now the 0% adjusted signal coming from SAFC is different voltage than the one from MAF, SAFC giving 1.02v while MAF is sending 1.1v signal.

Also O2 sensor consistently showed 0.31v since owning car(No O2 sensor connected, harness is sitting in bay unplugged). Cut wire from O2 harness, and spliced AEM UEGO NB signal into it. O2 consistently showing rich mixture, now because the 0.31v signal simply added w/e NB signal is giving, showing voltages anywhere from 0.6v to 1.4v.

Now car runs like **** at idle, beautiful cold-start up at 14.7 stoich, but keeps leaning out until full lean. Bad wiring or what else could it be, don't think it's vacuum leaks, boost gauge showing 20 on the vacuum. Any idea for fixes?

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Duncan's V37.......race car?

      By GTSBoy · Posted

      See if you can thermal epoxy a heatsink or two onto it?
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Also, I logged some data from the ECU for each session (mostly oil pressures and various temps, but also speed, revs etc, can't believe I forgot accelerator position). The Ecutek data loads nicely to datazap, I got good data from sessions 2, 3 and 4: https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-2?log=0&data=7 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-3?log=0&data=6 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-4?log=0&data=6 Each session is cut into 3 files but loaded together, you can change between them in the top left. As the test sessions are mostly about the car, not me, I basically start by checking the oil pressure (good, or at least consistent all day). These have an electrically controlled oil pump which targets 25psi(!) at low load and 50 at high. I'm running a much thicker oil than recommended by nissan (they said 0w20, I'm running 10w40) so its a little higher. The main thing is that it doesn't drop too far, eg in the long left hand fish hook, or under brakes so I know I'm not getting oil surge. Good start. Then Oil and Coolant temp, plus intercooler and intake temps, like this: Keeping in mind ambient was about 5o at session 2, I'd say the oil temp is good. The coolant temp as OK but a big worry for hot days (it was getting to 110 back in Feb when it was 35o) so I need to keep addressing that. The water to air intercooler is working totally backwards where we get 5o air in the intake, squish/warm it in the turbos (unknown temp) then run it through the intercoolers which are say 65o max in this case, then the result is 20o air into the engine......the day was too atypical to draw a conclusion on that I think, in the united states of freedom they do a lot of upsizing the intercooler and heat exchanger cores to get those temps down but they were OK this time. The other interesting (but not concerning) part for me was the turbo speed vs boost graph: I circled an example from the main straight. With the tune boost peaks at around 18psi but it deliberately drops to about 14psi at redline because the turbos are tiny - they choke at high revs and just create more heat than power if you run them hard all the way. But you can also see the turbo speed at the same time; it raises from about 180,000rpm to 210,000rpm which the boost falls....imagine the turbine speed if they held 18psi to redline. The wastegates are electrically controlled so there is a heap of logic about boost target, actual boost, delta etc etc but it all seems to work well
×
×
  • Create New...