Please help with this Learning View

I was having a bit of a rough idle and what felt like low power. I replaced the air filter (paper) and cleaned the MAF. Problem persisted. I pulled this LV today then reset the ECU. Now it almost stalls when I release the gas pedal.

 

Can anyone suggest where I should look for leaks? Happy to do a log, but not sure which parameters would help.

 

07 spec b

Infamous tune stage 1

SPT cat back (stock DP)

Plugs have 20k KM

 

(sorry, LV is in Metric)

Learned AF values don't look bad. Did you possibly get a bad tank of fuel? It looks like you are knocking quite a bit in the higher RPM range under load.

 

If your car almost dies after you reset the ECU, it may be because the ECU hasn't fully re-learned yet. Let the car idle for 10-15 minutes and see if the issue goes away.

Thanks Capn. I reset the ecu once again and this time made sure to let it idle until fully warmed up and stable. I was getting lots of knock though...rolled over the max count (34) 3 times.

 

I was wondering if it was bad gas. Would that cause all the knock? My tune is for 91 octane, but the last tank I put in was 94.

 

Went for a drive and took another snapshot: (this time in imperial, not metric)

looks pretty much spot on now. put it down to bad gas, test again in a few days for peace of mind

Thanks for having a look Chimera.

 

I've got just under half of that tank left. Should I keep going on it to burn as much as possible or dilute it with a top up?

And don't reset the ECU again, or at least pull an LV *before* you reset. Drive easily off boost until you're almost done with the tank, then completely refill with the good stuff.

Understood iNVAR, I appreciate your knowledgeable input. The LV in post 1 was prior to the reset. The second LV was after.

 

Would it be advisable to reset the ecu after I am through this tank? Or just let it re-learn?

Thanks Capn. I reset the ecu once again and this time made sure to let it idle until fully warmed up and stable. I was getting lots of knock though...rolled over the max count (34) 3 times.

 

I was wondering if it was bad gas. Would that cause all the knock? My tune is for 91 octane, but the last tank I put in was 94.

 

Went for a drive and took another snapshot: (this time in imperial, not metric)

 

Bad gas can do lots of weird things. When you were getting knock count increase as you mentioned, was it during idle/cruise or under load?

Your knock count can increase during idle and during some cruising. Some things that are loose in the engine bay and suspension can cause sounds that have the same resonant frequency as an engine knock. The key is that your knock count is not increasing under load.

 

If I were you, I would run the car low on gas and then re-fill. Don't try to dilute it. You can then do a reset afterwards and then pull another learning view after driving it for a bit to see if things start to clear up.

The knock events were during idle. I got maybe 10 knock events while driving, but I think only one or 2 were under load.

 

Will finish this tank see what happens on the next.

 

I appreciate the great advice. Thanks!

So I finished the tank with the suspect bad gas. Filled with 50 litres (13.2 US gallons) of shell 91 (same gas I had my tune done on - no ethanol).

 

I took a LV snapshot after filling, then reset the ecu.

 

Went for a drive and did some logging. Noticed that my IAM dropped down to .5625 after it had hit 1.000. Drove conservatively a bit more and IAM dropped even more to .0625!

 

Now I'm a little concerned. What would be causing this? Should I not drive the car until the problem is located?

 

Attached:

LV before reset

Log

LV after reset and driving

romraiderlog_20130712_171908.csv

Check for loose items under the hood. Rattly heat shields, brackets not connected, Coolant bottle fallen off, etc.

I already had a look see and found nothing obvious.

 

Metered the front O2 sensor and had a stable 2.5 ohms. Already cleaned the MAF.

 

Took off the IC to look for cracks in it or tears in hoses and found nothing. I'm not sure want to do next.

Looked at your log. Your WGDC stays at 0%, so when you're briefly at WOT, your target boost shows 16.01psi, but you're only hitting in the low to mid 8psi area (which correlates to running on waste gate boost). Your total timing is also very low at WOT (9 degrees) for such low boost and engine load numbers. You're pulling some timing here and there, but nothing major. You might have an issue with your BCS, or the waste gate actuator itself. Your waste gate is not functioning. I would start with that and go from there.

Looked at your log. Your WGDC stays at 0%, so when you're briefly at WOT, your target boost shows 16.01psi, but you're only hitting in the low to mid 8psi area (which correlates to running on waste gate boost). Your total timing is also very low at WOT (9 degrees) for such low boost and engine load numbers. You're pulling some timing here and there, but nothing major. You might have an issue with your BCS, or the waste gate actuator itself. Your waste gate is not functioning. I would start with that and go from there.

 

That's not correct. His boost and timing is that low because his IAM is that low. You have things backwards. Boost control is shut off as a safety measure when the IAM is that low.

 

The reason someone has low IAM is almost always due to knock, whether it's false or real. That much knock but with AFRs like his (which look right) is usually due to what BlazeRex suggested.

That's not correct. His boost and timing is that low because his IAM is that low. You have things backwards. Boost control is shut off as a safety measure when the IAM is that low.

 

Yes, this exactly!

That's not correct. His boost and timing is that low because his IAM is that low. You have things backwards. Boost control is shut off as a safety measure when the IAM is that low.

 

The reason someone has low IAM is almost always due to knock, whether it's false or real. That much knock but with AFRs like his (which look right) is usually due to what BlazeRex suggested.

 

That's right. I forgot about the IAM boost control disable at .2 IAM (stock parameters), disabling WGDC. I probably should not try and answer questions at 2 a.m. Thanks iNVAR.

 

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Haha we've all been guilty of it

My engine cover is only being held on by 2 popits since I lost the other 2. Perhaps the unsecured corners are rattling. I will remove the cover and log some more.

 

Could resonant frequencies (drone or gear whine) trigger the knock sensor?

 

I really appreciate the advice.

Is your car still idling rough? If so, try logging cylinder misfire for each cylinder. That can cause rough idling (as can other factors), but it's something you can check off the list, as well as making sure nothing is loose in your engine bay. I doubt the 2 missing pop-it's on your cover will cause false knock. I current am missing 2 as well. But, might as well get two more and eliminate that as well. While logging for misfires, might as well log your OCV's as well. make sure one isn't bad.

The rough idle went away after a cold reset, but I will certainly add those parameters when logging. I did watch the OCV's realtime a few days ago (nothing odd), but not the misfires.

 

Thanks for the suggestion.

No problem. eliminate what possibilties you can cross it off the list.

 

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I removed the engine cover and reset the ecu once again. Warmed up to a stable idle then went for a short drive. (still lots of knock at idle, but I can't hear any rattles....)

 

This log holds IAM 1 - I had to edit it for file size limit. I do see some knock correction taking place. What else should I be paying attention to?

 

I did have a couple of misfire occurrences at idle before logging. OCV's look fine.

romraiderlog_20130713_160228 - Drive2 .csv

I tried downloading the log, but all of the parameters appear to be in one cell for some reason

Odd. Here it is again. Thanks for looking 311logan311

romraiderlog_20130713_160228 - Drive2 .csv

Where are you located? (altitude, octane). Looks like your car is running better. Guessing your tuner set IAM to start at .75 (I do the same) and your car jumped to 1 quickly.

 

If you did have bad fuel, it might take a few tanks to get the knock to disappear. Like I mentioned, it looks better than your previous log and at least you are able to get your IAM to 1. Residual bad gas could explain the stuttering and the random misfires. Watch out for the large amount of timing being pulled at WOT. Keep logging and see if things continue to improve