Can't seem to fix IAM drop
 

http://datazap.me/u/celadrielas/tune-v-113?log=0&data=1

IMPORTANT NOTES:::

I currently have an exhaust leak from header to over pipe. Replacement header should be picked up tonight. Issue has existed since before leak

@ time 514.46, RPM 4749, 63% throttle, IAM Drops to .96


@ time 738.18, RPM 3229.75, 36% throttle, IAM resumes 1.0

Fuel 91 Octane
Format A01C (start map was the v1.53 OTS)

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I feel like I've exhausted my current knowledge and any help would be greatly appreciated

as the IAM drop is only occuring at a light load I'd suggest pulling back the inlet cam timing a bit as this reduces the natural compression ratio and cylinder pressures

ok. I'll give that a shot.

I noticed it when getting onto a freeway. Because of the exhaust leak, I didn't want to do a full pull

Don't you have my number? If so text me... I was considering going to the east side meet... I can probably lend a hand. Currently I'm on my phone so viewing that link is a tad difficult. Email me your rom and log file...

I think you guys were looking at the wrong knock type.

I think its more likely its the FLKC knock thats happening arround 5000 rpm and load 0.9 that is the issue you pulling -1 to -2 degrees just before and as the iam drops. The "Knock Correction" or FBKC in that log is very minor prior to the iam drop.

see extract from you log below
http://datazap.me/u/celadrielas/tune...zoom=4704-5199

fix you leak then see what it looks like, likely pull some timing around 5000 loads around 0.9

You could try the cam timing as suggested for the lower rpm lower load knock. or just pull about 0.7 out of the timing map. in that load rpm range.

Don't use "wideband afr" on oft unless you have changed the second o2 sensor to AEM and controller as it not calibrated for stock sensor. Use the front AFR sensor logs as "afr" and compare that to "afr commanded" that the ecu is targeting

Just glanced on my laptop while flashing my own car... why are you running 17+AFR at that load.... your MAF V @ 3.1-3.5V range is way off... your engine load value is being displayed much lower than it actually is thus advancing your timing. And your AFR is very lean.

I would not take much notice of that Wideband afr value unless he has correct wideband sensor fitted, read my previois post, he needs to log just AFR on oft so it logs front sensor.

@steve99 We've adjusted that and @nelsmar has been helping out all night.

Even at proper observations we were noticing a lot of knock and an assortment of other issues that he has helped me address. Thanks again for all the help everyone

@Celadrielas any insight into what he did to fix the knock and what other issues were going on?

I didn't realize that it was the wrong AFR... I logged it with my own hardware in person and checked things out. The last revision got rid of his knock on his way home last night and the AFR's are pretty close on target now.

I made him a custom MAF calibration, and a few minor tweaks to the ignition base map in spots that were prone to knock. His AFR was actually in the 13.5-15AFR range and was causing false load readings (0.8-1.0 load througout the power band which was a good 1-3 columns off consistently) which was advancing the timing excessively.

So he has fixed his exhaust leak ?

Weird the afr was lean oft tune generally run pretty rich ? has stock intake ??

He has an AEM intake. He had a rom from the OFT team that was supposedly for an AEM intake (with the MAF unit plugged in). He said he gave them a list of mods and that was the file he got back. I am thinking he simply got the wrong MAF calibration. Mistakes happen, no biggy! He also has a modified snorkel on the AEM which has a fair bit of turbulence. So I had to leave him a little off target on the top end and run it a tad richer than normal and a minor ignition tweak just to keep things in line.

I did a maf scale for a guy with AEM and yes it seemed to have some kind of turbulance/resonance so had to use a bit of manual smoothing , his trims were about 15% in places before scale, don't know if snorkel was modded as he was on other side of the planet.

awesome to hear you guys got it sorted :)

I do have the exhaust leak fixed as of today and the car is running without CEL. I am noticing 2 things I've not noticed before and the 1st is a light rattle / grinding noise when I am making a left turn and engaging first gear (like turning into a plaza) I triple checked all bolts and nuts and everything is still on and solid, so I don't know what it is. I am *very* fortunate to have Nelsmar's help with this. He's really made a significant difference in the way it feels and runs.

The second is a smell I can't identify. Since I am now using a used stock header to replace my stock header, I suppose there could have been oil in it or something depending on how nice previous owner / user was to the damn thing. --- *** RESOLVED *** smell is gone, so what ever it was burnt up in the exhaust

I am about to reflash to tune version 1.13.5 and we will go from there (so basically version 1.18 of this tune.) I need a replacement snorkle though.

EDIT::: http://datazap.me/u/celadrielas/cel-...5?log=0&data=1 FLKC pings when I shift into 3rd for a second

For those interested - @JB86'd , @steve99, @nelsmar

That is very minor knock -0.65 , it could also be due to the exhaust rattle you have causing knock sensor th think its knock. Check overpipe heat shields not the cause

I don't have the stock over pipe or any heat shielding on the over pipe, but I didn't check the heat shielding on the replacement header. If that's be loosened that could be the ever so minor grind I was hearing. I'm not hearing anything anymore though