[tb30570]

lately, my engine has been cutting out very briefly. It doesn't typically stall, it will just lose power and then it comes back again.

I checked the LTFT and the bank 2 is ~+20% on the highway. It drops to close to zero at idle and into the single digits in higher throttle positions.

Do you think whatever is causing the LTFT to be so high could be causing the cutting out? If not, what other parameter should I be checking/logging?

What would cause LTFT to be high on the highway but not at idle or in under high throttle positions?

[ferocity02]

What is Bank 1 LTFT?
What are the AFR's?
Post a log?
What fuel?
Tuned?

If Bank 1 LTFT is very different than Bank 2 then you may have an injector issue in Bank 2. Usually the injectors leak which results in very negative LTFT's on that bank. This is not your case, but still points to an injector issue.

[tb30570]

Originally Posted by ferocity02

What is Bank 1 LTFT?
What are the AFR's?
Post a log?
What fuel?
Tuned?

If Bank 1 LTFT is very different than Bank 2 then you may have an injector issue in Bank 2. Usually the injectors leak which results in very negative LTFT's on that bank. This is not your case, but still points to an injector issue.

Bank 1 LTFT was under 10%; AFT's were in the upper 14's so not actually running lean; HPFP and LPFP pressures were matching the requested values pretty closely; fuel is 93 octane E10; tune is cobb stage 2+ aggressive

What parameters do you think I should log?

I just installed 2 rebuilt injectors on bank 2 because I was getting a rich condition at idle on bank 2. No more rich condition at idle, but now I have a new problem I guess. I was wondering...if the injectors are rebuilt, are the values printed on the injectors still accurate?

[titium]

post a log up with some wot pulls freeway and idling

[ferocity02]

Originally Posted by tb30570

Bank 1 LTFT was under 10%; AFT's were in the upper 14's so not actually running lean; HPFP and LPFP pressures were matching the requested values pretty closely; fuel is 93 octane E10; tune is cobb stage 2+ aggressive

What parameters do you think I should log?

I just installed 2 rebuilt injectors on bank 2 because I was getting a rich condition at idle on bank 2. No more rich condition at idle, but now I have a new problem I guess. I was wondering...if the injectors are rebuilt, are the values printed on the injectors still accurate?

If they are rebuilt I would find it very hard to believe that the calibration values are still accurate.

[V8bait]

Originally Posted by tb30570

Bank 1 LTFT was under 10%; AFT's were in the upper 14's so not actually running lean; HPFP and LPFP pressures were matching the requested values pretty closely; fuel is 93 octane E10; tune is cobb stage 2+ aggressive

What parameters do you think I should log?

I just installed 2 rebuilt injectors on bank 2 because I was getting a rich condition at idle on bank 2. No more rich condition at idle, but now I have a new problem I guess. I was wondering...if the injectors are rebuilt, are the values printed on the injectors still accurate?

IMO rebuilt injectors are great, for stock cars. This is likely part of your issue although a log would help with stft/ltft/pedal/throttle/timing/afr, but may not show the cause still since most hesitations are so brief it's hard to capture in a log.

[Jeff@TopGearSolutions]

I don't think rebuilt injectors would have the same flow values as the originals. That may be the issue.

How long have you given the LTFT to adapt?

What do the STFT look like?

[ferocity02]

I would say at least one of the injectors on Bank 2 is giving you trouble and running leaner than it should. As a result, the DME is enriching the entire bank. This is bad because now some of the cylinders are running overly lean, and some overly rich, but the average is coming out correct. This is why the injector calibration values are critical. We must trust them otherwise the individual cylinders could be running far from the correct AFR.

I had a similar issue when my #6 injector was leaking. The LTFT was very negative... the DME leaned out the entire bank to compensate for the leaky injector. So #4 and #5 was too lean, #6 was still to rich. I pulled the plugs and saw that the top of the #6 piston of bright and shiny, the excess fuel cleaned off the carbon. #4 and #5 were running lean judging by the color of the plugs.

[titium]

have you reset adaptations? if not the dme will still be adapted to the old injectors.

I had a similar issue where I could feel a slight misfire between 2k and 5k RPM. Looking at logs showed lean AFR (15-16 to 1) both banks,maxed out negative LTFT and maxed out positive STFT. I was also getting codes for bank 2 post cat o2 sensor (delayed reaction rich to lean). odd thing was it cleared up post 5k rpm and AFR was fine..... reset adaptations and AFRs are perfect LTFT and STFT are within plus minus 10% and the code hasn't returned (it's been 2 months).

unless you're planning to sell the car in the near future I've never understood why people would buy used injectors that are prone to failure (being a pre 10 revision) from an unknown source.

for me the time and convenience of not breaking down, not having to work out what the problem is and not risking damaging an engine is worth far more than a couple of $100.

Try resetting adaptations if that doesn't work go buy yourself some new injectors install them and call it a day.

Originally Posted by titium

Try resetting adaptations if that doesn't work go buy yourself some new injectors install them and call it a day.

Which adaptations, specifically?

[titium]

Originally Posted by FCobra94

Which adaptations, specifically?

I reset all of them. lambda, air/fuel and octane should do the trick.

if you reset throttle adaptations be sure to wait 30-40 seconds before starting the car otherwise the car won't idle properly and you'll think you broke something....

[Jeff@TopGearSolutions]

Yea I'd skip throttle adaptation. Most annoying adaptation to work with when it goes bonkers. Good tip on waiting though, I always wondered what worked.

[titium]

Originally Posted by Jeff@TopGearSolutions

Yea I'd skip throttle adaptation. Most annoying adaptation to work with when it goes bonkers. Good tip on waiting though, I always wondered what worked.

yep learnt the hard way haha I think the official procedure is reset then turn ignition off, turn ignition on (without starting the car) wait the 30-40sec then start the car. I'm assuming it cycles through some process in that time.

[tb30570]

Originally Posted by titium

have you reset adaptations?

If this is what you mean, then yes



If you mean something else, then no and I don't know how

[tb30570]

Originally Posted by titium

post a log up with some wot pulls freeway and idling

I recorded some logs. Where can I upload them?

[tb30570]

When I figure out how, I'll post the logs.

The ECU may have done some learning because the logs I recorded didn't look the same as the live data I was looking at a while ago. Bank 1 and 2 are not that much different anymore on the highway. Both are in the teens at times, but I didn't see either one jump over 20. The engine did stumble a few times, but I can't even see where in the logs.

Today, the engine went into limp mode and I pulled the codes. The code was a P2AA3 camshaft sensor outlet signal interference. I couldn't find anything about this code, but I did find a few articles that said camshaft sensor failure could lead to engine stumbling. Do you think that's what is causing the issue?

[tb30570]

I figured out how to post data logs. There are 3 of them.

mixed driving:
http://www.datazap.me/u/tb30570/log-...9?log=0&data=1

highway:
http://www.datazap.me/u/tb30570/log-...9?log=1&data=1

idle:
http://www.datazap.me/u/tb30570/log-...9?log=2&data=1

[ferocity02]

Looks like you might have a bad injector in bank 2 judging by how slowly it goes full lean when you let off the throttle, and it never actually reaches full lean. Trims seem okay though. Bank 1 is also slow to lean out, but not as bad and bank 2.

Not sure what that cam code it about. I'd clear it and see if it comes back.

[tb30570]

Originally Posted by titium

for me the time and convenience of not breaking down, not having to work out what the problem is and not risking damaging an engine is worth far more than a couple of $100

I cannot replace one injector with a new one on the same bank as a legacy model. Replacing all three is $700. That's not pocket change, so I thought I'd try rebuilt injectors for $610 less.

[ferocity02]

Originally Posted by tb30570

I cannot replace one injector with a new one on the same bank as a legacy model. Replacing all three is $700. That's not pocket change, so I thought I'd try rebuilt injectors for $610 less. Seems pretty reasonable to me.

You can buy NEW injectors for around $138 that are properly tested such that the calibration values actually make sense.

http://shop.advanceautoparts.com/p/g...zoneAssigned=1

Running remanufactured injectors on the original calibration values makes no sense.

[tb30570]

Originally Posted by ferocity02

You can buy NEW injectors for around $138 that are properly tested such that the calibration values actually make sense.

http://shop.advanceautoparts.com/p/g...zoneAssigned=1

Running remanufactured injectors on the original calibration values makes no sense.

I wasn't sure about new aftermarket injectors. I had a bad experience with an aftermarket thermostat for the n54. Have you had good luck with aftermarket injectors?

[ferocity02]

Originally Posted by tb30570

I wasn't sure about new aftermarket injectors. I had a bad experience with an aftermarket thermostat for the n54. Have you had good luck with aftermarket injectors?

Lots of us, including myself, run aftermarket injectors. Some will say that they are the same as OEM just without the BMW markup.