Thread: Strange KR

Your injector duty cycle is over 100% when you are getting knock. And your fuel trims are high. I'd look for a vac leak.

But your total trims is like +12 to maybe +20. Not sure why you would be showing over 100 IDC with stock injectors with stock pulley. Can you post your tune? Have you changed injector settings?

It's too rich at full throttle. Anywhere from 10.2 to 10.8 commanded. Without a wideband I don't know how accurate that is to the actual AFR the wideband would show. We can't see custom channels you create using the EGR if that is your method of logging.

That could explain the high injector duty cycle. Cutting back to 11.0-11.5 could cut 10% from the IDC. Though I do forget if the IDC is accurate on the 2004+ computers, something in the back of mind says to me that that was a topic long ago but I can't put my finger on it.

I'd like some clarification on what the commanded to actual AFR is like. You should not have a large error between the two.

The part throttle knock isn't something I could give you a good guess at. Certain harmonics or a weird vibration maybe.

I have the same maths set up, if he's using the egr with an AEM..I haven't looked at many other's logs, so not positive I'm seeing what he's seeing. But I see around 14.7 at cruise, and when he goes WOT he's reading lean. He's commanding 10.7 and wideband is showing 11.7.

Tune looks ok. I assume it was running fine before, and you haven't made any recent changes? I didn't know about the IDC thing, so I got thrown off. Are you hearing or smelling anything odd? I still think you have a nasty vac leak. Your map is high during cruise when you get knock.

I guess I'm always on the mind set that commanded needs to match actual for fueling. That is a huge difference if computer asks for mid 10's but the actual is 11.5ish. That means the MAF calibration has been fudged to get you that value. Because if you were to zero out the rpm adder table and command a solid 11.5 AFR it probably put you in the low to mid 12's based on what we have already seen.

I'm not saying that's the cause for your knock issues though but it should surely be addressed. It may help with full throttle knock if indeed 11.5-11.7 is not ideal, some cars do like 11.0-11.3ish to keep knock at bay. You're running around 9-10psi in the current weather and that's slightly richer AFR is a good spot to be because as the weather cools the boost pressure may increase by a pound with more dense air.

Yeah man, I noticed his time vs rpm adder is pretty high. It's adding like .850 at 4000 rpm. Is that how zzp tunes work? Just throw fuel at it?

Dumb question, but did you smoke test before or after the current issue? Your map is reading like 85kpa at cruise. I'm used to seeing around 45. If it's not a vac leak then I don't know. But I'm on an 01 pcm, so I obviously don't k ow all the 04 quirks.

If I were you I'd compare a known good scan to your current scan. That map is high to me. Unless maybe your cammed. Idk

I was talking about scans of your own car. You don't have any saved when your car was running good?