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Discussion Starter · #1 ·
I have already looked up to see if anyone else having this problem, and it seems only one other person had it similar to me, but we have different setups, maybe the cause is different for me. This is my first post on this site, or any forum, so please take it easy on me.

My first mistake was buying Ktuner, because their customer service department people were incredibly rude to me and my tuner who is well respected in SCCA and Grand-Am racing winning multiple championships. Get Hondata.

Here is my setup. 2007 4 door si.
Relevant mods: Skunk header 4-2-1 (cat delete), OEM replacement rock auto RDX injectors, Ktuner.
Known problems:
-One of the pullies makes a whining noise. Not sure which one it is. If it is the alternator or AC, would it cause this problem
-Slight oil leak from the valve cover gasket.
-Rock auto RDX injectors.

After buying Ktuner and getting a earful about not buying Kpro, he agreed to tune my car which took no time at all. Car ran flawlessly for a few track days (we are getting it ready for SCCA national racing.) I did a few datalogs and noticed that the STFT was 12% at 8000rpm right before cutoff. My tuner recommended that I buy RDX injectors or FIC injectors. I installed the OEM replacement RDX injectors and adjusted injector sizing as well as dead times in the Ktuner software. Everything else in the tune is stock except the WOT enrichment which is set to 12.9ish. This is where the problem begins.

The car is excellent everywhere. Our STFT is under 3% everywhere except in the idle map. My current injectors need to give me 0.8% duty cycle to give me the correct AFR, but the car is at -31.25 STFT and 1.1% duty cycle. We are sitting at 11.3 AFR and if I turn on the AC (not a full race car yet) it goes up to 14.1ish. The strange thing is that once the car goes up to 31-34kPa, it idles perfectly at 14.7. When the idle falls to 29,28, 27, the afr drops drastically. In some cases I have seen 10.6. When I come to a stop the car sits a 14.7 and it slowly creeps down to 11s as the MAP slowly drops from 36ish to 27ish.

The AFR has gotten worse as the week goes on a few days ago, it was idling at 12.6 and 14.1 with AC.

Here are things that I have tried.
-Playing with the main trim
-Manually reducing the fuel in those load cells with the speed density tune
-Increasing IDLE TPS position at 0.
-MAF scaling
-disabling the MAF with a MAP sensor tune.
-disabling closed loop all together
-playing with corrections

I have not played with the tip-in fuel parameters (and I dont think it has anything to do with it).
I have done everything to confuse the car to lean itself out and nothing.
This leads me to believe that the problem is mechanical. I am not a mechanic, but some issues I thought of are:
-Bad Alternator or AC comp pulley is causing the idle to drop to a load cell that is below idle??
-Fake RDX injectors cant go below a certain duty cycle allowing the proper fuel and the richer it runs, the more the plugs foul and cant burn causing a negative feedback loop.
-IAC valve is dirty and isnt allowing air through?
-Ktuner is no bueno (the administration)
-Map sensor, O2 sensor, MAF sensor is bad?

It sometimes seems like Ktuner doesnt do a lot of what is shows it can do. I will ask for a specific fuel at a specific load cell and it will just ignore it (closed loop, open loop, all sorts of things disabled or enabled, you name it). Same with most of the parameters. I really feel like they developed this for the later models and the 8th gen is an afterthought. Not a very well put together platform to tune on for our cars. Get what you pay for. Garbage in garbage out. Same with my fantastic choice of injectors.

Anyways some ideas, thoughts, etc would be appreciated. THANKS!!!! :)


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