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Unstable AFR during transient conditions


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Hi All,

I realise that this is not really the place for getting help with the basics, but I am going to put my hand up anyway and see if there is any love.

Newbie here and just finally got all of my sensors wired up and my ECU in my car. I am experiencing some very interesting AFR fluctuations during the initial setup and would like to request the input of some more seasoned individuals...

First of all, the details: 
Evo 8MR 
GSC S2 Cams 
FIC 1050cc Injectors 
Stock fuel reg (presumed to be 43.5psi) 
Link G4+ Plugin 
Link CAN Lambda Sensor, Flex sensor 
Bosch IAT 
M&W CoP Kit  AJD300 - Day 11 (enrich and overrun changes) 2.pclr

Also a MAP EF2 turbo and bigger blah blah blah to support things. Not sure much else is relevant to the issue at hand as the car runs and goes like stink with the factory ecu (tuned with ecutek by a tuning shop on the GC so I cant get to any of the data) installed.

I have been able to get the car started and get it idling, revving up, and some very minor back and fourth movement in gear so far. My problem is that under transitional throttle conditions, my AFR goes all over the place. Basically any increase in revs or load (yes even if load remains the same) results in extreme leaning quite linear to how quickly I depress the throttle. Also, if I let go of the throttle in any great hurry, it results in a RICH condition.

I have been able to make my way through the rev range to about 3500rpm (while stationary ofc) while being incredibly gradual with it. So long as I increase the revs incredibly slow I dont get massive lean conditions, but that kind of rpm management is not going to be possible in any kind of driving scenario nor does it seem correct to me. I am also noting a fair bit of variation in the AFR at idle between startups, even after warmup enrichment expires.

I have tried increasing enrichment values and turning off overrun cut for the time being, but none of that seems to be making any major difference in stabilising things. I have a friend with a very similarly modded Evo 6 who I used as a reference for accel enrich.

Would love some suggestions of what to check and test. Part of me is wondering if my injector flow rate is way off the rated flow, or if my dead times are wrong (even though I have data for both). Kind of stumped due to a lack of experience. Have attached the map for reference.

EDIT: Added log file

AJD300 - Day 11 (enrich and overrun changes) 2.pclr

day 11 - 3 (final).llg

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I've just taken a quick look.  I dont see anything too major wrong in there but have a couple of suggestions:

  1. You have an aux 4 assigned as FP speed but under the pump speed control you have that function turned off.  If you are still using the stock FP controller then your pump is possibly running in low speed mode all the time.  Even if you are not using the FP speed controller, you really need to test FP yourself and make sure it is right.
  2. Turn off the IAT trim table.  In modelled mode air temp correction should be handled by the charge temp calculation.  Right now you will have twice as much air temp correction than is needed.
  3. In accel enrichment settings your "accel hold" should be 4inj events for a cylinder sequential setup.

edit: forgot to mention - does this car have mivec? I see you have an aux out set up as vvt solenoid but vvt is not set up.

Edited by Adamw
added a bit more
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Thanks for the suggestions Adamw. Optimistic about those suggestions and will try them in the morning.

EDIT: Posted reply on the phone while trying to multi-task and sucked at it... No car does not have MIVEC. Very interesting to hear about the IAT Trim Table and modelled fueling. Will post back with how it all goes. Cant consciously do anything with the car here after 8pm as the car will wake the dead across town nevermind the kids nextdoor. 

Edited by Sheik
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I have adjusted the accel hold enrichment events to 4 and disabled IAT Trim to no avail. Still have AFR moving around and massive leaning upon throttle.

The configuration in place for both accel enrichment setup and the FP Speed both came from the stock Evo9 base map. If it is set that way by you guys on the base map. I am afraid I dont have any information on how to configure the Fuel Pump Control with the existing system and it seems to want duty cycle info so I can see myself cooking a relay somewhere if I put the wrong values in here. Not really willing to "tinker" with it.

If you have any data for me that would be awesome, otherwise I may just have to bite the bullet and upgrade my regulator. I was hoping to avoid it for a little longer on account of being broke and those fittings costing a fortune. At this point though, its pretty much a massive unknown variable in this whole procedure. I just hope I dont go through all of this to find I just had shitty injector data.

Any further suggestions welcome. Many thanks for your weekend posts Adamw. :).


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Evo9 fuel pump should be setup like this:



Evo8 fuel pump should be set up like this:


I would use the evo8 settings on yours (i.e 2000RPM, 5%FF).  Your injector settings look realistic enough to me so I wouldnt expect them to cause any major running difficulties.



Edited by Adamw
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Thanks again Adamw. I will give it a crack tomorrow afternoon. Too far into the evening for such shenanigans now.

I dont know if it changes anything but I am making a pretty safe presumption (dont know the reality of it as I have not lifted the fuel cradle since I bought the car) that there is an aftermarket fuel pump. I am basing this on 1100cc injectors and E85. Either way it would have been a direct swap-in at a guess as there does not appear to be any changes to the wiring. 

I am starting to wonder if my Injector Timing event is drastically out due to the head modifications. I noted some variation there for my friends Evo6 tune over mine. His was at 320BTDC instead of the 340BTDC mine is at. More reading tonight and I might try my hand at reverse engineering the ignition advance table from my old ECU with the data I recorded via OBD2. 


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For a conclusion on this:

Put in the changes suggested by Adamw and tried again with similar results. Decided to stop being so timid and by the book and just fed the car more fuel. I was trying to stick to the theory of having relatively set % increases in VE (in some cases almost 15% between cells in some areas). My car just seems to want more drastic fueling adjustments in the sub 100kpa mark than I have observed in tutorials. Going to assume its a lumpy cam thing. 

Based on the info that Adamw gave me, I will assume that I would have ran into serious fueling issues later in the tuning process had I not asked this question as my FP Speed relay was not configured. Many thanks for the assist.

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