It depends on what part of the rpm he is looking at. At 4000 rpm the IDC @WOT is 56% on the Evo 9 I logged this past weekend. @ 5000 rpm it was 67% and % 6000 rpm it was 77%

 

Good call. When he stated one number for the IDC, I assumed he was talking about the max. I shouldn't assume anything when diagnosing a problem. He may have thought that the injectors would max out during the highest load.

 

6* at peak torque is pretty aggressive if those AFR's are correct. But, according to your log you are at 5* at 3500.

Are you tweaking timing map high octane #2?

Also, check your IDC at 6500-7000rpm.

I really think your wideband is off because you aren't getting alot of knock. If you where indeed running 12.5 AFR and 6* you would most likely see more knock.

Which wideband is it? Where is the probe? What are your mods?

*I had this same problem while tuning a car on the dyno. I maxed out ecuflash fuel at 7.4 and the wideband *in the tail-pipe* showed 12.5 at peak trq. I eventually cycled the power on the wideband, repositioned it, and it still showed the same. I swapped out the sensor for a new one, and it finally read normal.

 

I'm running 94octane gas. It's an AEM UEGO that I've had for about 4 months. Probe is right at the end of the downpipe.

Mods are drop in, mbc, tbe.

I'm almost positive it's not my wideband because I originally had a custom tune by dynoflash, and when I pulled the map that he tuned me for, his fuel map was 7.4s in a lot of the same areas mine is now.

He should have told me that wasn't normal.... but now I know better. I'm 90% sure it's my walbro.

 

Thanks for the advice everyone. I'll update after I swap fuel pumps tonight.

 

Your knock counts are pretty low for being that lean, though.

 

hehe. I was going to ask about the fuel pump, but figured you still had the stock pump. Could be another dead Walbro. If your Walbro is dead, and you need a better (but more expensive) pump, check out the Power Enterprise 245 lph pump:

http://www.power-enterprise.co.jp/fuel_pomp.html

Its Denso pump, so it should be better quality, and its 38 mm dia, so it should bolt in with minimal mods. The US distributor says that they can get it for around $220.

 

It seems like I read about a walbro failing once a week or so! I don't think I've ever read of a stock pump failing...

 

what is your afr numbers at idle? does it misfire slightly at idle?

 

well,

we are something similar...on a few evo ix's... with ic pipes, turboback, mbc, intake and 24psi peak, 20 at redline... but im mostly seeing it up top, above 6000rpm...

bigger injectors soon.

cb

 

Alright I switched back to my stock IX pump. The Walbro was definitely the culprit of my high AFRs.

I went out and did a run without modifying the map, and got these results.
Note the majority of the run was beyond what the UEGO could read as it is <11.0 AFR. However torque peak hit 11.6 AFR.




Instead of taking the time to retune the entire fuel curve, I copied the high octane fuel map from a friend of mine's flash, and pasted it into my map, without any modification at all. This map was targeting high 11s AFR.

Results below, only a partial run.



Note the high 12s, low 13s AFR numbers. Honestly, this made me think my AEM UEGO is off by as much as a point. If I was really hitting 13.1 AFR, I would have way more than 3 counts of knock recorded. Although I realize with the timing map being different, the AFR result will be different to his map.



CLIFFS: Stock IX > WALBRO, my wideband is off But everything's good now.

 

Jeff - As i indicated in my pm to you, yes the UEGO is very inaccurate. You must have the older Uego which cips at <11.0. Glad you got your issues resolved though!

 

The UEGO claims an accuracy of +-0.1, just like all the other gauges out there. Just because it's calibrated from the factory (there's a laser-burned resistor in the sensor connector harness, unique to each sensor) doesn't mean it's bad. Of course, if you have an old sensor, then that is a problem (for any brand).

The idea that your tuner saw this fuel pump problem and just maxed your fuel tables out without telling you about it is a real joke. WTF!? I mean, forget about all the advanced timing vs. lean AFR debates.. not telling you was simply irresponsible!

 

The problem with the Uego is that it does not allow you to re-calibrate the WBO2 sensor. It is well known that WBO2 sensors "drift" with use. The built-in resistor becomes less and less accurate the more you use them. They will be accurate @ stoich, but in the 11-13 area (the areas freaks like us are concerned about) they lose accuracy. So the OP's only option is to get another sensor simply because he cannot re-calibrate the existing sensor. WBO2 sensors should last approx 40K miles if you can re-calibrate them for accuracy. If you cannot, then you will have to get another sensor.

 

Since the method of calibration is different, I'm not sure you can make a direct comparison between the free-air type of cals used on most sensors and the factory cal'ing done on the AEM. However, according to my manual, the spec on the sensor is: 80,000km nominal on unleaded fuel, accuracy of +-0.7%. (I assume that's a percentage of Lambda, not AFR)