High LTFT's usually mean vacuum leaks. What are your MAF readings at idle? They should be in the 3-4 g/s range with the AC off.

 

In the first pic you can see my MAF reading at idle (600 - 700) it was 3.8. If it was a vacuum leak my STFT would be high too and they would drop when I increase load. My STFT stay within normal range.

 

Post oxygen sensor voltage graphs


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Currently in bed but I will first thing in the morning

 

Production date on your 330ci?

High positive LTFTs at hot idle are almost always vacuum leaks. Read this thread for how to do a smoke test cheap and easy.
https://forum.e46fanatics.com/showthread.php?t=1261077

What are these values at hot idle?
Both STFTs
Both LTFTs
MAF value in g/s

 

The first pic has all of that info. STFT was 0.0%, 0.8%. LTFT was 24%,25%. RPM was 697. MAF was 3.38 g/s. And if it was a vacuum leak, wouldn't the STFT be high as well? And the values should go down with load but these don't.

 

I took some more screenshots, it has the codes and more graphs. My emission isn't setting and when i get gas it always stalls on start up, could that be because the DMTL? I also included the freeze frame from lean code.

 

Okay I reset the adaptions with inpa and then I went back to Scanmaster and the STFT where -25% and went down immediately during load. My MAF is good, so is it fuel deliver problem?

 

Have you smoke tested for vacuum leaks?
https://forum.e46fanatics.com/showthread.php?t=1261077

 

Nah, I have to build one but this isn't vacuum leak i have negative fuel trims.

 

Don't be a douche. Please.

You can graph the MAF and determine whether it has failed. You cannot test the MAF that way. The actual reading is dependent on atmospheric pressure and conditions, which I strongly doibt you have the equipment to control. But I may be way off. The MAF fails by losing accuracy, normally by under-reporting. So it can look mostly right on the chart but be off meaningfully enough to cause fuel trims.

Resetting adaptations is not like resetting codes, though I could see how you would reach that conclusion. The ECU does adapt to the big one and sensor conditions through the LTFT, and it alters those adaptations in real time through the STFT. However, it adapts them in both directions. If you fix a vacuum leak, the ecu will lower the LTFTs. It might take a few drives, so bmw provides a reset so technicians don't have to drive your car around to see if they fixed the issue.

There is no such situation as Ltft being wildly out of range and stft being in range as being healthy. The LTFTs should be +/- 2.0, and you get codes at around 11-12%.

You had extremely high LTFTs, which means that your the ecu was dumping fuel in. You can look at the STFTs at idle and cruising speed, which can help direct your attention to fuel system/sensors versus vacuum.

But I strongly suspect that you have not quite understood that you have an old engine and if any of the precat sensors, vacuum seals and hoses, fuel pump or fuel filter are original, they should all just be replaced.

It's like your responding without even reading or maybe your getting confused. I never said resetting the adapts was anything like resetting the codes, I know the difference between the two. I never said that it was healthy. READ CAREFULLY: My STFT where IN RANGE (look at the graphs) my LTFT was 20+%. The STFT continued to be in range even WITH LOAD and the LTFT never dropped. THAT is the reason for resetting adapts. It has already learned to add more fuel which is why the LTFT where 20% but STFT stayed within range. When you reset adapts, you clear what the ECU has learned in LTFT so it doesn't compensate automatically. That why after the reset it read -25% on both LTFT and STFT because the ECU is getting to stoichiometric ratio with no learned adaptations. And I already told you I replaced the Fuel pump and fuel filter so why would you mention it again? Not trying to be a douche but your reading comprehension is not the best.

 

ScanMaster is pretty good. OP has provided some good data. It's not yet clear what exactly is the problem, although high positive fuel trims at idle is normally vacuum leaks. Maybe more background information could help us help him?
Did the engine used to run fine with no trouble codes and near 0% LTFTs?
What event triggered the current issues?
Is the engine, and especially DME software, all BMW factory stuff? No tune or other goodies here?
What did the smoke test reveal? Any vacuum leaks?

 

ScanMaster is pretty good. OP has provided some good data. It's not yet clear what exactly is the problem, although high positive fuel trims at idle is normally vacuum leaks. Maybe more background information could us help him?
Did the engine used to run fine with no trouble codes and near 0% LTFTs?
What event triggered the current issues?
Is the engine, and especially DME software, all BMW factory stuff? No tune or other goodies here?
What did the smoke test reveal? Any vacuum leaks?

I bought the car like this.

The main symptoms were: stalling after refueling and loss of power in the high end (high load). It acts like its not getting enough fuel or fuel is being cut off. Intermittent delayed throttle response.

Everything is factory.

I'm going to do a smoke test today if I can find all the materials today and I'll post results later today.

 

Looks like he has a massive (vacuum) Evap leak.


i m throwing a code. p1447
https://forum.e46fanatics.com/showthread.php?t=377193


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Here's some spit-balling thoughts...

Stalling after refueling: I wonder if fuel is getting into the evap system, say the vapor canister is saturated? Maybe remove the evap hose from the purge valve and see if liquid fuel is in there. Should only smell like fuel (vapors).

Compression/leak down tests: have we confirmed the cylinders are good?

Clogged cats: exhaust back pressure test, or simply remove both pre-cat O2 sensors and have a short drive to see if power returns.

For diagnosing fuel system issues, I like to just look at the STFTs when the engine is fully hot. They're instantaneous, so reflective of current running conditions.

Smoke test: eager to see the results of this.

Does ScanMaster do logging of PIDs? That***8217;s one feature of OBD Fusion we use a lot.

What's the production date on your 330ci? Or, better yet post the last 7 VIN numbers so we can look up the exact car configuration on realoem.com.

 

Here's some spit-balling thoughts...

Stalling after refueling: I wonder if fuel is getting into the evap system, say the vapor canister is saturated? Maybe remove the evap hose from the purge valve and see if liquid fuel is in there. Should only smell like fuel (vapors).

Compression/leak down tests: have we confirmed the cylinders are good?

Clogged cats: exhaust back pressure test, or simply remove both pre-cat O2 sensors and have a short drive to see if power returns.

For diagnosing fuel system issues, I like to just look at the STFTs when the engine is fully hot. They're instantaneous, so reflective of current running conditions.

Smoke test: eager to see the results of this.

Does ScanMaster do logging of PIDs? That's one feature of OBD Fusion we use a lot.

What's the production date on your 330ci? Or, better yet post the last 7 VIN numbers so we can look up the exact car configuration on realoem.com.

I changed purge valve a few weeks ago and i i checked again during the smoke test and their is no fuel. Their were no leaks during the test but Im going to do another because I don't think I have enough pressure because the jar was leaking (diy smoke machine). But I pulled the oil cap to see if there was smoke and their was, so I was getting smoke in the engine. I reset fuel adapt again and and now my STFT is at 27% and LTFT is at 0%. The STFT decrease with load so it definitely a vacuum leak (look at graph in attachment). But I didn't see any leaks with the smoke test. Cleared the codes and SES didn't come back but it usually take a 30+ miles for it to come back on.

Don't have time right now to do a compression test but maybe next weekend, I have to go buy the set at harbor freight.

I'm not touching the o2 sensors because they are reporting normally and I have never had any o2 codes.

And i did log the PIDs (See the attachment I previous posted and they one on this reply, their all logged on one graph with different colors each PID. I've been posting my logs ever since the first post.

I'm not near the car right now but Ill post the vin when I can. I don't know the production date but Ill get the vin.

 

Vacuum test from yesterday

https://youtu.be/mO-tzR67tUA

 

Vacuum test from yesterday
https://youtu.be/mO-tzR67tUA

That video is marked private, so none of us can watch it.

 

It sounds like you may have already figured this out, but to be clear, the only time STFT will be out of the normal range is if there is a problem the computer hasn't adapted to yet, or if it is so bad that there isn't enough adaptation available with LTFT. The LTFT is basically a 3D graph that accounts for all possible engine loads and RPMs, so it will account for the exact current fuel demand of engine, as long as nothing has physically changed recently.

To rule out a fuel delivery problem I would graph the fuel trims at wide open throttle. If the car can provide enough fuel to keep it from going even leaner at WOT, then you probably don't have any problem with the fuel system.

Like several people have said it sure sounds like a vacuum leak, except for having a pretty normal MAF reading at idle. I would make sure you're getting enough smoke into the intake plumbing before ruling that out. Check for smoke from the dipstick tube as well.

First thing I would do because its so easy, even though its a long shot, is take a look at the air filter. I've seen a really bad one of those give most of the symptoms of a vacuum leak. I suppose it was because it was disrupting the air flow through the MAF.

 

To rule out a fuel delivery problem I would graph the fuel trims at wide open throttle. If the car can provide enough fuel to keep it from going even leaner at WOT, then you probably don't have any problem with the fuel system.

Heres is my most recent graph with WOT up in the 3k+ RPM range, the LTFT go down to 0% and the STFT go to 25% (Look at attachment). So i think I might have fuel delivery problem. I haven"t done another smoke test yet but that will be for tomorrow.

 

OP's VIN: PL15166
https://www.mdecoder.com/decode/pl15166

07/2004 330Ci AT

 

Hmm, yeah I'd say that definitely doesnt rule out a fuel problem. It looks to me like it doesnt get a whole lot worse with more throttle, but it defienitely doesnt get better either.

Whatever the conditions were in that last graph, the car seemed to like them, at least while the engine was at around idle speed. With the long term around +30 and the short term around -20 that almost gets you in the "normal" range of around + or - 10.

After seeing these graphs I'll be surprised if the car has any significant vacuum leaks unless its in conjunction with more significant problems. It looks to me like it gets worse the more throttle it gets, backwards of what you'd expect from a vacuum leak.

 

Hey Gio, if you like we can set up BMW Standard Tools software on your Windows laptop, and then update both your DME and EGS modules to the latest factory BMW software. After that we can use INPA to look at the engine parameters and see what***8217;s going on. You have my number.

 

Gents,

chasing a similar issue ...

What should my STFT and LTFT be if things are tight and working correctly ?

I have eliminated the vac leaks and now i am going to use a known good MAF to test to see if things are buttoned up ?

Are there "expected values" at COLD, WARM, HOT, DRIVING?

If they are specified someplace please point me there as I am all for being self sufficient (obviously not in this case).

thanks in advance

 

Might be best if you start your own thread to avoid confusion with OP***8217;s issues.

Fuel trims should be as close to 0% as possible. If LTFTs go below -10% or above +10% for a while, trouble codes are triggered.
STFTs are instantaneous and move around a lot. LTFTs are averaged over time and more indicative of the overall fuel management condition.

Suggest you read up on them. Here***8217;s one explanation.
https://www.obd-codes.com/faq/fuel-trims.php

 

It was a failing MAF. I also replaced the exhaust and intake camshaft sensors for good measure. The MAF caused the lean code which cause a dumping of fuel which then cause a fuel tank vent valve code and subsequently my high LTFT and Intermittent stalling. Everything is perfect now. No codes. Cleared my adapts as well and readings are within range.

 

Glad you got it solved.
What are the brands of the old and new MAF sensors? Genuine BMW, Siemens/VDO, other?

 

Genuine BMW to VDO

 

Does it seem like the old MAF was over-reporting air mass?
I ask because I had a similar problem with negative LTFTs on a genuine BMW MAF that was less than 5 years old, and only solved it with a new VDO MAF.

 

Over reporting. Their was build up on the wire which i cleaned but I don't know how old it is so I just went brand new to save me the headache.

 

I have two cans of MAF cleaner here, that remain with 90% full. FWIW I've never had a satisfactory long term outcome with cleaning MAF's.

Cleaning (if it doesn't damage it) one and if there's a change for the better only proves a new one is needed.

 

I agree. I didn't get the MAF code until probably 2 weeks ago which confirmed my diag. The LTFT was high because it just "learned" to dump fuel to compensate for the "unmetered air" (oil residue) on the hot wire. The interesting part was when I got the CAN torque reduction on my recently rebuilt transmission. I had no idea the MAF would tell the ECU to limit torque. I regained a good amount of power and it pulls very nice. I still need to do my front suspension overhaul and coolant system overhaul and she'll be perfect.

 

Weird. I was right.

 

Post your quote to prove it

 

 

Just glad it is sorted!

Somebody on here has a signature that says "it was the MAF"

It is always the MAF in the end

 

Somebody on here has a signature that says "it was the MAF"
It is always the MAF in the end

OnTheFence