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Old 12-05-2016, 05:16 AM   #21
jfoj
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Quote:
Originally Posted by dothehundo View Post
I looked at the drive logs, and your throttle values don't look OK to me. Your Absolute throttle position (%) are between 10 and 15 the entire time, it looks like an almost straight line on the graph. On mine, for a comparison example, I see a range from 9 to 97.

Does your throttle response feel coarse? Were these taken shortly after an adaptation reset, or after a while when it settled back to its odd behavior?
Not sure this data point is such a factor based on the type of cruise. Also with the way the tool is gather data at this point some of what we are seeing may be masked.

It also appear the drive location is relatively flat as well.

I usually do not see the Absolute Throttle Position pop over 20% on many of the cruise situations, but it may warranty a bit more investigation.

I think to way to get a better idea about the Absolute Throttle Position value would be to Log a normal drive where the OP has to get up to speed, I would expect to see more throttle valve movement in this type of Log.

In case you were unaware the ICV actually does a lot more air control under lighter load than the actually throttle body. The ICV is more of a secondary high precision throttle body. This is while under light load there is often a flat line for the Absolute Throttle Position. Typical highway cruise I rarely see ATP spikes higher than 20% and these tend to be spikes.
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Old 12-05-2016, 05:27 AM   #22
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I dont think thats the problem. most of the logs i've posted are idles or on my way to work in the rush hour, where its simply not possible to go full throttle.

I found my old maf yesterday (thought i threw it away when i bought the new one), cleaned it and put it in the car. felt better this morning, although the maf reading still drops to 3 g/s.

heres the log from the drive, you can see that my throttle position went up to 87 (1016 and following): https://www.dropbox.com/s/hogorhekx2...83325.csv?dl=0
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Old 12-05-2016, 05:35 AM   #23
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If and when you get to drive more spirited, how does the engine perform?

I see you were able to get one good spike in the Absolute Throttle Position on the way to work in rush hour!

Also want to confirm the MAF is in fact a 3 wire MAF, I expect it is.
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Last edited by jfoj; 12-05-2016 at 05:39 AM.
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Old 12-05-2016, 05:42 AM   #24
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Quote:
Originally Posted by jfoj View Post
If and when you get to drive more spirited, how does the engine perform?

Also want to confirm the MAF is in fact a 3 wire MAF, I expect it is.
It always feels better after going full throttle. thats why i thought the throttle body might be the problem, that it kinda forgets the full throttle position or something like that.

how can i check if the maf is a 3 wire maf? there are 3 connectors in the plug it thats helping. if needed i can take a picture later on.
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Old 12-05-2016, 05:59 AM   #25
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Something about finding the floor seems to put a smile on most BMW owners faces!

You can just look at the MAF you took off the car or if you happen to pop the hood there will only be either 3 or 5 wires on the MAF. I expect 3 wires, but given this is a BMW, every time I think I understand ever configuration that exists, I learn something new.

You had a question earlier that I did not get a chance to respond to:

Quote:
Originally Posted by sebograf View Post
perhaps someone has a clue, whats the problem with my car. i don't know if thats a cause, but i watched my maf readings drop from 4.0 g/s when starting this morning (when idle was down to 700 rpm) to 3.1 g/s when reaching my destination. Is that right? Why is it dropping when the car warms up?.
Under cold start the VANOS and ignition timing is altered and the MAF value will be higher at a given RPM then when the engine is fully warmed up, so it is normal for the the MAF value to drop as the engine warms up. Additionally as the IAT temperature rises the amount of air measured will drop as well, assuming all other factors do not change. So this is fairly typical behavior.
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Old 12-05-2016, 06:19 AM   #26
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Quote:
Originally Posted by jfoj View Post
You can just look at the MAF you took off the car or if you happen to pop the hood there will only be either 3 or 5 wires on the MAF. I expect 3 wires, but given this is a BMW, every time I think I understand ever configuration that exists, I learn something new.
Thats how my maf looks like:
maf

Last edited by sebograf; 12-05-2016 at 06:19 AM.
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Old 12-05-2016, 06:42 AM   #27
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OK, thanks for confirming this.
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Old 12-05-2016, 04:14 PM   #28
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I agree that the throttle inputs are likely being masked, given the data rate / lag. I was looking at the extra drive data which included accelerations, so I thought one might be viewable there.

This throttle position can be tested with the ignition on / engine off and then modulate the throttle through its range. But now we have the confirmation in the latest set of data that the throttle sensor range is normal.

This data looks normal to my layman eyes, with a couple of minor exceptions. It appears to me that the engine is taking a long time to warm up fully. It's getting to an intermediate level, ~40C, and then not moving for a long time. Soft failing thermostat? Or could be an effect of the cold weather, something I'm not familiar with

I see a couple sporadic zero values on the O2 sensors, but they might loosely correspond to open loop (fuel status 4), which I have seen on my car, so I think is normal?

I'm not sure how to interpret the speed vs RPM data here as I'm not familiar with SMG at all. I'm wondering if you may need to use a tool like INPA to look into the transmission controller, maybe that's the source of the gearing issue.
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Old 12-06-2016, 02:35 AM   #29
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After driving a bit more with the old maf, the car feels good. It shudders a bit when cold, but thats nothing to worry about i think. when warmed up, its driving and shifting smooth.
But after changing the maf, the ltfts are nearly instantly back to -2/-3.
I will try to change the injectors again, i have a second set on hand, maybe my cleaning wasn't helping after all.

@dothehundo:
i noticed too, that some values have sporadic zero values. i think thats a problem with the logging, because sometimes even the input voltage drops to zero (and i think thats something that would be noticeable while driving).
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Old 12-06-2016, 09:08 PM   #30
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So the car is running OK now, and no problems with the transmission? I would keep logging, and keep an eye on the LTFT, and the coolant temperatures, the slow warmup is something of a concern.

Now I'm sure the zero O2 voltages are a problem with the data. I just ran a test on a couple of my old datalogs, on a 300 mile drive, both ways, to see if a zero O2 sensor reading correlates to open loop. I compared reported open loop values (fuel system = 4) to O2 sensor values at zero, and did a check to see if the data might be misreporting open loop (I used load < 11 and RPM > 1000, meaning, engine is producing less than at idle, but above idle, so the car is in gear and decelerating, so it should be in fuel cut)

The first log had 5900 data points, there was a lot of heavy traffic, so, more than usual decelerations. I was open loop 7.9% of the time, O2 sensor zero 6.8% of the time, and O2 sensors zero but not reported open loop 1.3% of the time. But of those, the majority of them showed I was actually in deceleration but the fuel system wasn't reporting that. The second log had 3800 data points (almost no traffic, so a faster drive), Open loop 2.6%, Zero O2 2.2%, Zero but not open 0.70%, and the same result with those few data points.

So in summary, I found a 98+% correlation between zero O2 sensor readings and open loop. The <2% I chalk up to bad data.

Quote:
Originally Posted by jfoj View Post
As for Fuel Rate, this is not of much use from my point of view, it is fictitious value that is not directly pulled from the DME/ECU. It is calculated based on other parameters and I have not seen this as a very accurate and reliable tool. Maybe I will take another look at some of these "calculated" values, but I prefer to work with Live data.
I did another test comparing airflow (which is calculated off of a voltage) and fuel rate (which is calculated off of airflow), on a month's worth of data, and I found that they differ by a constant factor 99% of the time. I discovered this a while back and that's why I started logging fuel rate, as I'm interested in fuel data.
Again, the difference is just bad data reporting, but...it seems that the airflow is less likely to get stuck on stupid than the fuel rate, and this tends to happen around startup. So, jfoj, you're correct in using airflow and not fuel rate, 99% of the time

Quote:
Originally Posted by jfoj View Post
To your last comment about LTFT's not being a problem if they are in the +/- 8% range. Not sure where you are coming from and what background you have but historically these cars will trigger Lean codes at 10%! So if your car is hovering around 8% on a regular basis, there is NO margin of error before there is a DTC triggered for a fuel mixture problem.

I have looked at literally hundreds of these cars and thousands of cars overall. Each make and model has its own peculiarities and I know what a "good" E46 typically looks like. LTFT should really never be Negative and anything above +3.5 LTFT should raise eyebrows and concern for anyone. At +5% or greater you SHOULD be taking action to understand, identify and correct the LTFT values.
I was probably wrong about the +/-8%. Though I've been floating between positive 5-8% for a while now, and the car seems to run great, I've noticed that minus 4-5% isn't as good, the plugs tend to get fouled up then.
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Old 12-06-2016, 10:01 PM   #31
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Keep in mind under Deceleration with Fuel Cut Off the engine turns in to a large air pump and the Pre-cat O2 sensors tend to overshoot the 0.1 Volt and will often go to 0 Volts.

You will/should see the Fuel System Status go from 2 to 4 during these deceleration conditions.

And by the way, very few Apps support Fuel System Status or properly support Fuel System Status. I pushed the OBDFusion developer hard to add the Fuel System Status as it is a GOLDEN piece of data to have and Log.

One thing to consider is to Log with a reduced number of PID's. I often request the full 22 or so PID's that the E46 supports because I often need to see the BIG picture. But as we start to narrow in on a specific problem I will often shrink the number of PID's to Log down to 4-8 PID's. This will often give much faster updates and often better granularity when looking for squirrely or elusive problems.
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Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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Lower hose temp switch O-ring - BMW #13621743299

Last edited by jfoj; 12-06-2016 at 10:04 PM.
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Old 12-06-2016, 10:32 PM   #32
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Right, but open loop can also be triggered by other situations, like wide open throttle, all report fuel status 4, so to find fuel cut you have to filter out the other situations. I have noticed from the dash gauges that it won't trigger unless the RPMs are above 1500, then fuel cut will end when RPM drops to 1000. This is on my manual, others may be different.

I am surprised that other apps don't show fuel status. I have a Scangauge that's 10 years old and it shows that.

Interesting that fewer PIDs can increase the data rate!

Thanks for the info!
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Old 12-07-2016, 07:24 AM   #33
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Quote:
Originally Posted by dothehundo View Post
Right, but open loop can also be triggered by other situations, like wide open throttle, all report fuel status 4, so to find fuel cut you have to filter out the other situations. I have noticed from the dash gauges that it won't trigger unless the RPMs are above 1500, then fuel cut will end when RPM drops to 1000. This is on my manual, others may be different.
I am quite aware of the Open Loop under WOT situations, this is because the Closed Loop Fuel Control is too slow under fast RPM rise and this is to protect the engine from Leaning out as well.

The issue is very few people actually drive around at WOT on a regular basis and when we are usually dealing with driveability problems, these tend to be in the daily driving lower RPM ranges. I rarely ask for WOT Logs for many reasons, partially because rarely are problems during WOT, partially because people are not usually spending a lot of time at WOT.

All the Logs I ask for are typically not under WOT conditions, I usually want to benchmark the vehicle and compare some of the known behaviors. Very much like what I do when working on computers, I first want to know what I am dealing with, things like Hard Drive fill, RAM Usage, Running Processes. I can tell in seconds what I am dealing with on a computer job, unfortunately there are FAR more variables when dealing with vehicles. A much more dynamic environment.

Often not always an exact science and many of the sensors are soft failing or degraded and not hard failures. OBDII does not always pick up problems with soft or degraded sensors and intermittent problems often leave very little clue or telltale signs.

Sometimes it is a best effort and often you have to figure out what is working right to figure out what maybe wrong.
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Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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Old 12-09-2016, 02:09 AM   #34
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Over the last days the shuddering/jerking was coming back.
ltft of bank 1 was staying at -1.6/-2.3 where Bank 2 was at a good 0/-0.8.

Yesterday i had the stupid idea of changing my injectors to the second set i had on hand. after work, it was already getting dark, but i've done it before so no big problem, what could possibly go wrong. replaced all the injectors, started the car it was running really bad, i had misfires on 3 or 4 cylinders, car was running really shitty. so i had to take out my flashlight and put the first set back in, hoping that it would at least run normal again - and it did, thank god. but nearly 2 hours of working for nothing in the end. car was driving really smooth this morning, but i think thats because i disconnected the battery while working, so all adaptions values are back to 0.
here's a log from my morning ride to work, not really much to see i think. ltfts dropped to -0.8 o both banks again.
maybe i have two injectors that are not running perfect, before they were both on bank 1 and now they are divided on bank 1 and 2. i will get me some injection cleaner for the fuel tank and see, if thats helping.
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Old 12-09-2016, 02:27 AM   #35
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Hi Sebograf

Did you say that your ltfts dropped in magnitude after replacing the maf with the old original one? If that's true then maf is causing the negative ltfts?
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Old 12-09-2016, 02:33 AM   #36
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No, they went back to zero (because of the change i think). Afterwards they were dropping to -1.6/-0.8, but thats better than the -3/-2.4 I had before so the new maf was giving me worse results than the old original maf.
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Old 12-09-2016, 02:40 AM   #37
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That's what I have experienced too.

I had an old maf (not original but manufactured by Lucas as replaced by a technician a few years ago) which gave -0.7/0.0 ltfts before I replaced it with a VDO/Siemens which is giving me -5/-3 ltfts that is worse that the old one. The reason I replaced the Lucas was that it threw a MIL with code P0102 (maf low output). I cleaned the maf plug contacts extensively but it still threw code. So I replaced the maf with a VDO\Siemens maf and I have no P0102 since then. The engine does definitely pull better and has a more linear power output with the new maf though.

Last edited by MTX-4; 12-09-2016 at 02:42 AM.
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Old 12-09-2016, 05:00 AM   #38
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Both of my mafs are (supposedly) original vdo/siemens mafs, first one came with the cars, second one was bought on ebay from a big reseller.
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Old 12-09-2016, 05:08 AM   #39
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sebograf and MTX-4 I have questions for both of you. These questions may or may not have been provided at some point, I just want to make sure there is no data left out.

What kind of fuel do you have available in your area? Is this a 10% Ethanol mix fuel or a 100% gasoline?

What is the history on the Pre-cat O2 sensors? Have they been replaced recently on each car?

What problem are we trying to correct/resolve here? LTFT values or something more specific? I do not want to fall in the trap of worrying about LTFT when there may be a more specific problem you are trying to solve and the LTFT are a side effect or not even a contributing factor.
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Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

Temp Info - http://forum.e46fanatics.com/showthread.php?t=964491

Hidden OBC Menu - Check Voltage, Temp, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

E46/E39 GM5 Door Lock Info - www.bmwgm5.com

Lower hose temp switch O-ring - BMW #13621743299
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Old 12-09-2016, 05:44 AM   #40
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im only using super plus (thats how its called here in germany), thats 98 octane fuel with up to 5% ethanol.

pre-cat o2 sensors are still the original ones (with now nearly 140.000 km or 87.000 miles).

My main problem is, that after driving a while, my throttle body adaption gets bad and the car gets jerky, clearing it and clearing my ltfts works for a while, then it gets bad again.

i dont know if my ltfts are causing that problem or they are getting bad because of the problem.
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