Can't seem to fix IAM drop

[Celadrielas]

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

[350matt]

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

[Celadrielas]

Originally Posted by 350matt

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

[nelsmar]

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...

[steve99]

Originally Posted by 350matt

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

Originally Posted by Celadrielas

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

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

[nelsmar]

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.

[steve99]

Originally Posted by nelsmar

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.

[Celadrielas]

@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

[JB86'd]

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

[nelsmar]

Originally Posted by steve99

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.

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.

Originally Posted by JB86'd

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

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.

[steve99]

Originally Posted by nelsmar

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 ??

[nelsmar]

Originally Posted by steve99

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.

[steve99]

Originally Posted by nelsmar

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.

[Koa]

Originally Posted by Celadrielas

@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

awesome to hear you guys got it sorted