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Subaru 3000rpm rare target AFR


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Would you please take some time to help me solve the problem.it had been a headache to me for a long time.Thank you very much!!

My car is 06 Subaru WRX has those mods below:
ECU LINK G4+ Xtreme
Garrett GTX3076R
Manley 83 mm crankshaft
CP 8.5:1 cr piston
Id1000cc injection and fuel rail
Perrin front intercooler
Cosworth cams intake 278 exhaust 272
Dual valve spring
JE1.3 cylinder gasket
ARP cylinder headstuds
The problem is when I do full throttle pull or small throttle cruise  the afr reading is gonna jump around at 3000RPM which can cause lean condition. Above or below this rpm will be fine.
Attempts have been made such as change the fuel calculation model or the injection timing, fuel injection delay, or target air-fuel ratio change. This problem is still there.
I've been trying to solve the problem for months,my God.it's killing me.I hope you can help me figure out what's wrong about the  settings!
Again.Thanks guys.
Log and ROM attached!

yy (2) (1).pclr

Log 2017-08-13 6;59;00 pm 3 wot.llg




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As steve said, you could try moving the vac line for the fpr from the num 4 runner and tap into the vac line on the bottom of the plenum that would go to the bov on the stock car.

But in all honesty, I would 100% revisit the entire fuel map.  It looks like the rocky mountains.  Out of all the subarus I have tuned, I have never had one with a fuel table that looks like that.  

There are some instances, with some cars, where you will have to have a ton of variance from one rpm/load site to the next to keep afr stable.  But that is typically for high compression/large cam N/A cars.  

Also, why does your throttle only go to 80% FP until you get to 5k rpm?  It is set up like that in the e throttle map. 

Edited by Brad Burnett
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That lean condition starts right when your acceleration enrichment stops and the effective injjector pulse width does actually drop a little so it looks like you simply dont have high enough fuel table numbers at that point, or you need your acceleration fuel enrichment to last longer. Your fuel table kind of shows a higher value at 2500-3000rpm which you maybe just need to expand up a few hundred RPM but as Brad says, the whole fuel table is very spiky in general.

You've also got half a dozen knock detections at about the 9 second mark in that log (around 6000 rpm) which your knock control has dealt with, but they look "real" in that with a few degrees of timing pulled the knock stops, then as soon as the knock timer expires half a second later and the timing gets put back, there is another knock detection.

I'm guessing the 80% ethrottle target until 4500 rpm is intentional and maybe for basic traction control? You've also got a 2% minimum ethrottle target at all RPM's which may mean your engine breaking is quite light and revs may even hold a little between gears as your throttle never fully closes. If you drop this to 0% target above say 2500 or 3000rpm you'll still be able to idle but the throttle plate will close completely on decel.

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I agree with Steve and Brad here, based on the shape of your fuel table in that area you almost certainly have some sort of resonance in your FPR and/or MAP sensor.  Usually changing the length of hose or take off location will correct it.

Check this video from about 3:00 for an explanation:  https://www.youtube.com/watch?v=4QF5BmQtXZA 

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I agree with Steve and Brad here, based on the shape of your fuel table in that area you almost certainly have some sort of resonance in your FPR and/or MAP sensor.  Usually changing the length of hose or take off location will correct it.

Check this video from about 3:00 for an explanation:  https://www.youtube.com/watch?v=4QF5BmQtXZA 


hi guys! still got the same problem happened. 

i change the vacummtube by connected it to the oem bov with harder tube and about 40MM length to avoid pressure change. still the same.

then i changed the fuel regulator to a bigger size one still noting helps.

I started to think is it the problem of the injector?failure at certain pulses?

thanks guys.i will attach logs later.please help me out.


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Just looking through you calfile and map now and will just type down what i see or what sticks out to me on the fly. Relevant or not...

- Your IAT comp table looks weird. The general rule of thump is 10 degree equals about 2.5 - 3% fuel. Yours isnt even close to that rule. Dont know if its the one supplied by the basefile or not though..

- Why not modeled fuel mode?

-Accel load correction doesnt look right.

- Fuelmap DOES look like the Himalayas. Although a fuelmap rearly (if ever) turns out a smooth as the experts say it should this one is over the top (pun intended)

- ECT ignitiontrim. I would range that table further over 90 degrees so that you can pull timing at high ECT`s. Its now spanned to just 90 degrees.

- Idle ignition table could use some work...

- Fuel pump speed control isnt turned on. Can i assume you have only ONE pumpspeed on this car?

- I dont know the car but... You have left and right VVT outputs on.. However there is only ONE VVT position sensor configured (DI 2) ??

- Boost by gear wastegate trim. Set that way on purpose?

-Back to VVT.. The targettable is all set to 0`s... I imagine that doesnt help the issue much..

- Your logfile turned all my lables on my log pages into chineese or something so i cant figure much out from there. Sorry..


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Hi there

Have you tried getting someone to help you with a multimeter to monitor the voltage on the fuel pump when you drive and get these issues. I have read through all the great help suggestions and the next couple of things come to mind:

1.) You have a voltage drop on the fuel pump which is causing the fuel pressure drop at thise conditions you complain about.

2.) You might have a collapsed fuel line/pipe that is causing starvation when the pump tries to pump a higher volume ( this is normally at high rpm/boost) but check 

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