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Old 01-18-2013, 03:05 AM   #461
glhx
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I received the item that allows me to use the torque pro app today.

vacuum 24 according to torque pro
engine rpm 700
engine rpm in drive bounces to 550 and then goes to 640 and stays.
coolant temp was 84C
throttle showed at 10

where does torque pro give me fuel trims and o2 electrical readouts. It does show a live o2 chart. I didnt know what i was looking at so i had no idea what it was telling me. bank1 and bank2 were behaving differently on the graph.

The main thing i found was that my SAP pump was gone. It was not receiving power at the plug even though the fuse was good. Maybe the relay is bad. When i find the relay ill test it. I took the sap out and ran 12 volts to it. I found it to not work at all.Upon taking the SAP apart all the way down to dismantling the electrical motor. I found that the plastic base that holds the brushes was burned and melted. The rest of the motor was fine. The SAP hose to the control valve was heat cracked on the inside and crumbling on the inside only.

~The control valve was vacuum tested individually with a vaccum hand pump.
~The solenoid controlling it was working. The vacuum to the control valve was 18.....torque pro showed 24 in live data....my vacuum pump showed 18.
~The control valve itself held 24lbs of vacuum when i tested it separately by pumping it up with the hand pump.
~The control valve opened when vacuum was put on it and closed when it was taken off.

I could not blow through it when it was closed and could when it was open telling me the control valve was fine.....I ordered a gasket for the control valve anyway and will give it a thorough cleaning.

If thats the case then why was the motor melted.....just the motor. none of the other plastic showed signs of melting. I found lots of Sand under the SAP air filter but The bearings were fine.

I think it could be that maybe the relay malfunctioned and didnt turn the SAP off causing it to melt. That could be why the relay is no longer giving power but the fuse is good. Maybe a larger relay would be better. The relay im sure gets hot and was only design to be working for 90 seconds.

I did clean the control valve with seafoam recently. maybe some of the chunks from the large hose jammed it up and were able to be freed with the cleaning.

on another note. I dont think the SAP has ever worked since ive owned the car. I listened to one working on you tube and i have never heard sounds like that out of my car. I did listen to it with my ear next to the SAP the other day and it made noises for 90 seconds but they were not loud at all. I could barely hear the SAP running. my ear was pressed to it.

Could this be why my car is running so rich? Average gas mileage is decreasing and is now down to 19 on the obc. The 02 sensors were plugged in correctly and the connections were cleaned. I will test fuel pressure tomorrow. I know the O2 sensors like to see this SAP air and are maybe black due to unburned fuel...but still....not both at the same time.

Last edited by glhx; 01-18-2013 at 03:36 AM.
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Old 01-18-2013, 05:06 AM   #462
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If you SAP pump is not running at all, you should have a constant CEL for problems with insufficient airflow and O2 sensor problems.

I am starting to think you have A LOT more going on and quite a bit more work to do before your care is sorted out.

Do you know for a fact your CEL is working and had not been disabled?

What does do you have actively at the moment.

I would suggest you start a complete new thread as I think you will be working through a a systematic check and confirm operation and unfortunately I do not think you will be able to resolve everything with a single component or system repair.

I have a feeling your thread will end up looking and playing out as this one - http://forum.e46fanatics.com/showthread.php?t=954362

You may also want to order BMW Scanner 1.4.0 and/or get a cheap VAGCom cable and try to get a cheap or free copy of INPA.

These are more advanced tools that may come in handy for gather further info.
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Old 01-19-2013, 01:11 PM   #463
PainBreak
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I'm not sure if this is exactly the best place for this, but given the similarities, and jfoj's expert knowledge, I think we may be able to make some headway. I believe it has gotten worse as the temperatures have gotten colder, but that is only speculation.

2004 325i, automatic, just turned over 100,000 mi

Cold starts: Perfect
Idle: Perfect
Codes: P0171 and P0174
Symptoms: Engine hesitation under load, between 2,000-3000RPMs
Items Replaced: Thermostat, Lower Radiator Hose, Temperature Sensor. This wasn't related to the issue, but I've noticed it more after these items were replaced.
Known Bad Items: Just behind the MAF there's a small Y connector with two small hoses coming off of it. One of those hoses is rubber for a ways, then turns to plastic. In my earlier analysis of this issue, upon inspecting this part, I noted the rubber potion had dry-rotted. The dry-rot resulted in it breaking in two during my inspection. I have temporarily capped both ends. This has not changed the symptoms of the issue in question.

How to reproduce: Get on the interstate, and at 60MPH make sure the transmission is in 5th gear, then accelerate moderately, but not enough to engage the kickdown (passing gear) mechanism. Car will "buck" as power cuts out repeatedly, in a rhythmic pattern (~100 bpm) until either it gets over 3,000RPM, it kicks down, or you start going downhill, which sufficiently decreases the load.

I am going to check to see if there are any additional codes that have cropped up, as it's been a couple of weeks since I've checked them. I will edit this post with any additional information I find after my test drive. I do have an ELM327 OBDII dongle and Torque Pro, so I can monitor things if need be.

Thanks in advance for any assistance you can provide.
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Old 01-19-2013, 01:18 PM   #464
E46er75
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I'm starting to think that there is simply no solution to this cold weather related issue. I have yet to hear anyone successfully fix the problems. Yet, when the warmer weather comes these threads die off and all goes away...
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Old 01-19-2013, 03:10 PM   #465
jfoj
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Quote:
Originally Posted by PainBreak View Post
I'm not sure if this is exactly the best place for this, but given the similarities, and jfoj's expert knowledge, I think we may be able to make some headway. I believe it has gotten worse as the temperatures have gotten colder, but that is only speculation.

2004 325i, automatic, just turned over 100,000 mi

Cold starts: Perfect
Idle: Perfect
Codes: P0171 and P0174
Symptoms: Engine hesitation under load, between 2,000-3000RPMs
Items Replaced: Thermostat, Lower Radiator Hose, Temperature Sensor. This wasn't related to the issue, but I've noticed it more after these items were replaced.
Known Bad Items: Just behind the MAF there's a small Y connector with two small hoses coming off of it. One of those hoses is rubber for a ways, then turns to plastic. In my earlier analysis of this issue, upon inspecting this part, I noted the rubber potion had dry-rotted. The dry-rot resulted in it breaking in two during my inspection. I have temporarily capped both ends. This has not changed the symptoms of the issue in question.

How to reproduce: Get on the interstate, and at 60MPH make sure the transmission is in 5th gear, then accelerate moderately, but not enough to engage the kickdown (passing gear) mechanism. Car will "buck" as power cuts out repeatedly, in a rhythmic pattern (~100 bpm) until either it gets over 3,000RPM, it kicks down, or you start going downhill, which sufficiently decreases the load.

I am going to check to see if there are any additional codes that have cropped up, as it's been a couple of weeks since I've checked them. I will edit this post with any additional information I find after my test drive. I do have an ELM327 OBDII dongle and Torque Pro, so I can monitor things if need be.

Thanks in advance for any assistance you can provide.
You currently have lean codes, I believe you have no idle issues?

Do you have freeze frame data for your lean codes?

If your lean codes only pop while cruising 30+ MPH, then is is likely a MAF or fuel pump.

You need to get the Torque Pro addon to monitor fuel trims. You need to post fuel trim data at both idle and 30+ MPH constant cruise.
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Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

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

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Old 01-19-2013, 03:17 PM   #466
jfoj
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Quote:
Originally Posted by E46er75 View Post
I'm starting to think that there is simply no solution to this cold weather related issue. I have yet to hear anyone successfully fix the problems. Yet, when the warmer weather comes these threads die off and all goes away...

Not sure where you are getting your data, I believe that all but maybe 1% or less of these cold weather issues have been solved.

What happens is everyone shows up with a 10 year old car with 125k+ miles on it and expects it to run like it did the day is was purchased without ever doing any maintenance on the car!

Kind of get out of the car what you put into it?

So if you have a problem, suggest you start a new thread and outline CLEARLY, what car and mileage you have, what your problem is, what maintenance has been performed, what parts have been replaced, what data you have gathered and maybe someone can provide some feedback.

I think we have resolved some rather complex issues and if people take suggestions provided, the majority of the cars have been fixed.

Almost all of these problems are intake and crankcase air leaks and worn and non optimal sensors that are over 10 years old.

Yes, once the weather warms up, most of the people do not bother to resolve their problem, the next cold season the problem just gets worse.

Many of the Fanatics are VERY predictable, kind of like yourself who I would bet falls somewhere in the situation I described above.
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Hidden OBC Menu - Check Voltage, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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Old 01-19-2013, 04:31 PM   #467
PainBreak
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Quote:
Originally Posted by jfoj View Post
You currently have lean codes, I believe you have no idle issues?

Do you have freeze frame data for your lean codes?

If your lean codes only pop while cruising 30+ MPH, then is is likely a MAF or fuel pump.

You need to get the Torque Pro addon to monitor fuel trims. You need to post fuel trim data at both idle and 30+ MPH constant cruise.
I don't have any idle issues. It idles like a champ.

When I checked it today, I also had a P2974 and pending P2973, which are O2 codes. I did have a freeze frame that showed the code popped at idle (763RPMs), and the fuel trim was ~7% on one bank and ~13% on the other. I think that was the freeze frame from the O2 code though, because that doesn't make sense for the lean code.

The BMW dealership says they will charge me $125 to check if the DME code is up to date, and if isn't, they'll flash it. If it is already up to date, they said I'm still out the $125 because they charge 1hr labor minimum.

Edit:

Okay, I went for another test drive.
First, I monitored the short term fuel trims. At idle, both banks right around +20%. Sure sounds like a leak to me...
Next, I drove it to Advance Auto. At highway speeds, flat ground, steady accelerator application, fuel trim was anywhere from +5% to +15%, but more low than high. There was a lot of fluctuation, however, but never going up to +20%.
Purchased a new hose to replace the dry-rotted one coming off of that Y adapter on the intake.
Replaced that hose.
Monitored the idle fuel trims again. They were pretty steady at about +5% on both banks. Looks like replacing that hose did something!
Drove home. Fuel trim was all over the place again. I was able to get the engine to stumble again, at about 75MPH, roughly 2700RPMs. Fuel trim went up to 26%, but I'm not sure if it was a delayed reading, as the fuel trim always seems to spike some when letting off the accelerator. Fuel trim fluctuated a lot again, with a few >20% spikes, particularly when letting off the accelerator.
Arrived at home, monitored idle fuel trim. Still steady at about 5%.

Here's a graph of about 10 seconds worth of data while the car was "stuttering."


Last edited by PainBreak; 01-19-2013 at 07:01 PM. Reason: More educated info.
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Old 01-19-2013, 07:37 PM   #468
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Not sure I would go jumping into the dealer for a DME update on an almost 10 year old car at this point. If there were problems with phantom codes, the car would likely have been into the dealer in the first 4 years.

You need to actually graph the O2 sensors from cold start as well as graph them while you are driving. You should look this post over for ideas - http://forum.e46fanatics.com/showthr...light=monitors

Your fuel trims should be less than 3%.

When in doubt, put your $125 toward maintenance on your car and not at the dealer, there is not a software fix for a engine with old sensors and fuel delivery/air fuel mixture issues.

Depending on how old your pre cat O2 sensors are, they are likely time for replacement? Bosch should be about $50 each on Amazon.

If the problem is mostly with Bank #1, I would change the fuel filter and make sure the vacuum hose to the fuel pressure regulator is in good shape.

My gut is telling me that your fuel pump is going soft?

DISA, CCV are also very likely problems.
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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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
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Old 01-20-2013, 12:40 AM   #469
PainBreak
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Quote:
Originally Posted by jfoj View Post
Not sure I would go jumping into the dealer for a DME update on an almost 10 year old car at this point. If there were problems with phantom codes, the car would likely have been into the dealer in the first 4 years.

You need to actually graph the O2 sensors from cold start as well as graph them while you are driving. You should look this post over for ideas - http://forum.e46fanatics.com/showthr...light=monitors

Your fuel trims should be less than 3%.

When in doubt, put your $125 toward maintenance on your car and not at the dealer, there is not a software fix for a engine with old sensors and fuel delivery/air fuel mixture issues.

Depending on how old your pre cat O2 sensors are, they are likely time for replacement? Bosch should be about $50 each on Amazon.

If the problem is mostly with Bank #1, I would change the fuel filter and make sure the vacuum hose to the fuel pressure regulator is in good shape.

My gut is telling me that your fuel pump is going soft?

DISA, CCV are also very likely problems.
I purchased the car less than a month ago, and before that it's always lived in a warm climate, so I'm not working with as much information as I wish I had. It's entirely possible that it's never exhibited these issues before, but I also subscribe to the mindset of "buy hardware, not software" and "think horses, not zebras." I troubleshoot for a living, but not air/fuel mixture problems.

I did log the O2 sensor info, I just didn't make it part of that graph. I also logged a couple of trips this evening, and was able to get the stumbling to occur as well.

Here's what I can see about the stumbling. Going into it, the Bank 1 #2 O2 sensor shows .675v and Bank 2 #2 shows .699v. As the stumbling occurs, Bank 1 drops to .649v and Bank 2 to .235v. ST Fuel trim for bank 1 went from -1.56 to +15.625 to -14.843 over the course of 5 seconds. ST Fuel trim for bank 2 went from 0 to -25 to +23.437. RPMs went from 2621 to 2793 with 85% throttle. MAF rate stayed pretty steady at around 55 g/s.

I don't show any data from Bank 1 #1 or Bank 2 #1, but maybe I didn't let it run long enough before tagging those to log?

The data's so all over the place throughout the logging that I don't really know what to think. It's a bit difficult to wrap my head around.

The only reason I can't imagine it being the fuel pump is that at WOT there's no hesitation, for as long as I want to keep the pedal mashed to the floor. It pulls as hard as I would expect it to, through all the gears. I would think that would be the most fuel pump taxing thing to do. Maybe I am wrong?

I just don't want be the guy with the list of 17 things he's replaced trying to track down what's wrong.

Edit: I just went and checked again...and I get nothing for O2 Volts Bank 1 Sensor 1 and O2 Volts Bank 2 Sensor 1 from Torque Pro. Does anyone know if this is expected behavior?

Last edited by PainBreak; 01-20-2013 at 01:47 AM.
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Old 01-20-2013, 05:36 AM   #470
jfoj
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Your car has 4 O2 sensors.

They should be:
Bank 1, Sensor 1 - Pre cat cylinder 1-3
Bank 1, Sensor 2 - Post cat cylinder 1-3
Bank 2, Sensor 1 - Pre cat cylinder 4-6
Bank 2, Sensor 2 - Post cat cylinder 4-6

The post cat do not do much for fuel control, only really there to help monitor SAP warm up and cat efficiency.

Torque Pro should be able to monitor all O2 sensors.

I would remove your DISA and inspect it per the beginning of this thread.

You also need to read the 2nd link below in my signature on soft failed fuel pumps as well. And yes people have had soft fuel pumps that seemed to run find under WOT, this is because WOT switches to basically an open loop, fixed fuel map and ignores the O2 sensors for the most part. The fixed fuel map errs on the rich side to reduce the possibility of leaning the mixture and causing the combustion temps to rise too fast/high and reduce the risk to engine damage. So WOT will basically cover up to an extent a soft fuel pump.

Also since the fuel supply comes to the rear of the fuel rail, the front cylinders tend to be starved for fuel before the rear cylinders. So many times bank 1 suffers more and may so more lean than bank 2!

If you have not replaced your fuel filter, you need to do this as well as it also has a built in fuel pressure regulator.

If you have only had your car 1 month, you NEED to ASSUME nothing has been done as far as maintenance.

If the MAF looks new or newer, there are a lot of bad/crappy/counterfeit MAF's in the market as well.

But I would put my money toward a fuel pump before I would replace the MAF anyway.

You need to replace spark plug and plug boots, fuel filter and fuel pressure regulator vacuum hose, you likely need at least the CCV lower oil return line replaced, you need to inspect the DISA and you likely need to replace the pre Cat O2 sensors (the ones under the hood).

You also need to make sure the O2 sensors are connected properly, sometimes the easy thing to do is unplug then one at a time and see what bank codes get triggered. There have been a lot of situations where the harnesses get plugged in wrong. Once you know which hardness is which, label them!
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Fuel pump failures - http://forum.e46fanatics.com/showthread.php?t=929501

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

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Lower hose fan switch O-ring - BMW #13621743299

Last edited by jfoj; 01-20-2013 at 05:37 AM.
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Old 01-26-2013, 01:01 PM   #471
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Amazingly informative thread... your other links as well... thanks... I will be doing some additional maintenance as soon as I fix my current problem and actually some if it during this fix.
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Old 02-05-2013, 06:12 PM   #472
glhx
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just to throw this in here....

my LTFT are +10
STFT are normal +3/-3........while cruising
......................................while revving with no load
......................................while idling

So where is the extra fuel coming from.......it is coming from acceleration only

if your LTFT are at the top of their range +30/-30....the computer is saying.....you are too lean or too rich and i cannot adjust STFT to go back toward 0 or within range.....so then STFT go up to whatever the LTFT cant do.

In my research this is exclusively caused by a vacuum leak.

so whats wrong with my car.....I dont know yet.
fuel pump pressure or FLOW under load
air leaking in under load
maf sensor is lying
o2 sensor is lying.
exhaust leak

fuel pressure at idle should be 50.....fuel pressure at 4000 rpm should also be 50lbs

Maf in G/sec should be 3.8 to 4. something at idle

what is the mirror for in the top of the MAF sensor housing???

Last edited by glhx; 02-05-2013 at 07:48 PM.
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Old 02-05-2013, 07:30 PM   #473
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Mirror in the MAF housing??

What??? Not sure what you are seeing in there.

I know what the Bosch MAF modules looks like for my M5 and I think what they use on the 325. I need to pull my wife's MAF on here 330 and look at it. It should be the original on the car, we are 2nd owner and car was a CPO so no aftermarket stuff has been put on the car.

BTW, I have not been able to get my hands on the 330, its the wife's and between schedules sometimes it is hard to get my hands on it.

But I have been playing with my daughters VW Beetle 1.8t and the fuel trims do not spike high lean when hoping on the throttle in her car, short term may go up about maybe at the most 2-3 then drop back close to where they were before I jump on the throttle.
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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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
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Old 02-05-2013, 07:46 PM   #474
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I just noticed it today. there is a 1/2" by 1/2" or so square reflective surface at the top of the maf housing.

I dont think fuel trims are ever supposed to go into a high range ......ever.

the computer is always compensating for the amount of air coming in. trying to keep it stoich. If it reads more air....it sends more fuel.
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Old 02-05-2013, 07:50 PM   #475
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But your STFT is spiking - or negative, correct?
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Solve your misfires, lean codes, rough idle - http://forum.e46fanatics.com/showthread.php?t=897616

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, Temps, Fuel Level - http://forum.e46fanatics.com/showthread.php?t=239619

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

Lower hose fan switch O-ring - BMW #13621743299
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Old 02-05-2013, 08:02 PM   #476
glhx
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my STFT goes to +7 or +10 only during acceleration. for some reason the graphs ive done dont show it well.

i watched it happen....stepped on gas fuel trim shot up....let off they went back down......like clockwork...every time i stepped on it they spiked up.

obviously when i step on the gas under load a lot more air is coming in all at once. maybe some of that air is coming from a vacuum leak that idle is not powerful to overcome but air velocity is.

or.....like above in his post....hes at wide open throttle thinking the fuel pump has to keep up. it does...and it doesnt.....it sends more flow on the way up to WOT.....but once its there it doesnt need much to keep it there..........when I stomped on the gas the other night....I was logging. I saw 4500 or so rpm......Maf went to 128g/sec
Fuel flow went to 10lbs. But to keep it there.....the fuel flow went to 3 lbs. I didn't have any +10 trims at wot so I'm assuming this fuel flow behavior is normal. Now that I suspect lean condition under load. It brings me into a different thought process on diagnostics. At first we just knew it was lean but didn't know why. Now I know where the extra gas is coming from. Only acceleration under load

Last edited by glhx; 02-05-2013 at 08:10 PM.
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Old 02-16-2013, 12:31 PM   #477
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evening guys help please! I have a problem with my e46 m54 2.2 170hp engine, when I turn the machine cold and nn use it for 24 hours it's okay for 15 seconds then it starts vibraren for 30-40 seconds and the light comes on engine! I provided the diagnosis and says misfire in cylinder number 4! then once that is heated and everything is fine does not present any defect, to solve this problem I've replaced the cendele, the flow meter, bobbine, clean injectors, disability, CCV (Crank Case Vent), SAP air control valve vacuum line! !

nn hour longer know what else to do and the problem is not risolot. I was thinking about it on fire ahahaha

and I forgot for a few days but that machine had a loss of power now nn is more like before!
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Old 02-19-2013, 12:58 AM   #478
Shesgota323
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Join Date: Jan 2013
Location: California
Posts: 21
My Ride: 99 BMW 323i
I found this write up extremely helpful, was getting 14 codes. Misfires on all cylinders, fuel sensors, fuel control bank etc... Upon inspection the intake boot was torn. $27 later shes purring like a kitten again! Thanks for taking the time to write this up!
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Old 02-19-2013, 01:10 PM   #479
glhx
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Join Date: Jan 2012
Location: Middle Tennessee
Posts: 697
My Ride: 2002 BMW 330ci
As Just to update my problems here.

It was caused by a bad maf sensor. The maf was under reporting air or showing not enough air going into the intake manifold. It mostly affected fuel trims going high during acceleration. My ltft were around 12 for both banks. Even though the Maf SHOWED not enough air......it doesn't mean that excess air wasnt going in. The excess air was going in. The maf. Just wasn't reporting it.

My maf
was fine at idle.....for the most part, it was only during acceleration when the problems occurred. We researched the maf and it was inconclusive, but everything pointed to a Chinese made maf sensor. It looked identical in every way to a stock maf. My new one has a Z after the part number which is located on top of the square in the maf.

The Chinese maf failed at around 20k from it being new.
;
A dirty maf. Can cause the same problems. The dirt creates a coating on the sensor. The coating acts as an insulator. The air that is supposed to flow over the Maf wire now flows over this dirt coating and throws off the reading. Hence under reporting air flow and causing lean codes.

The Chinese made one. Well.......they can reproduce plastic castings and housings. I guess they either don't like platinum. Or they don't like quality. Platinum is the coating on the maf. Wire that allows it to stay hot and its costly. Either way they can't copy the technology to make a. Good maf.

Last edited by glhx; 02-19-2013 at 01:11 PM.
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Old 02-19-2013, 01:29 PM   #480
glhx
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Location: Middle Tennessee
Posts: 697
My Ride: 2002 BMW 330ci
Fuel pump

On the intake boot there is a connector we call the F connector. It looks like an F

The SMALL VACUUM LINE goes to the fuel pressure regulator.

Test this line to see if the diaphragm is holding vacuum. Hook it up to a vacuum pump and pump it up. See if it holds. Pump it to 20 on the gauge.....no more. If it doesn't hold there is a leak. The regulator can't do its job without the vacuum it needs
R

FUEL PRESSURE........should be 50lbs or very close, it should also stay there at all times. High rpm low rpm doesn't matter. Even under load. 50lbs
When you turn off the car it should stay at 50lbs.

If it doesn't show 50 its probably weak. If it doesn't hold 50 its probably weak.

So you've looked at it at idle and its 50. You revved the engine and its 50.......don't stop there. You need to check it under load. So how do you do that. Step on the brakes. Put the car in gear and rev the engine.....up to at least 2500rpm. I did it till 5000 and spun the tires some......and overpowered the brakes but the car didn't move much. If it stays 50 under load. Then your pump is probably good and your filter is probably not stopped up. When I bought my car I replaced the fuel filter.....and CCv....vacuum lines.,,,,,vacuum caps on the back of the intake and the lines to the secondary air pump.

O2 sensors
I've found that screen shots don't really work well. You want to see the bouncing up and down signal from .7 to .1........there are variations in the bouncing. If all you see is bouncing between like .2 and .6......that's not good.

We almost need a graph of it. Best graph is from cold start so we can see when all 4 of them go into closed loop.
Run the data for 2 minutes. Get o2 at idle, 2500 rpm cruise, and normal driving.

Torque pro will graph o2. Then send the data to your e mail.....then take it out and use excel to graph it.

WHAT IS THE LOOP.(OPEN OR CLOSED)... when the car is cold the computer uses its own programming to adjust engine fuel. It uses maf sensor air to figure out how much fuel it needs. The o2 sensor is not involved at all.
When the o2 isn't involved.....its not IN THE LOOP, its not giving information to the computer. Its not part of the loop or the computers inner circle when the car is cold. The is is called open loop. When the car warms up. The computer then wants the o2 sensor to join the loop. This is closed loop. The o2 and the maf sensor then work together to control fuel. Keep in mind the o2 sensor does not read fuel. It only reads oxygen. The Mafia sensor does not read fuel.....just air flow.......and neither sensor controls fuel. Only the computer does that. That is the computers main job......just to control fuel. It does this by opening the injectors for a longer time or keeping them closed for a longer time. How long it keeps them open for is determined by the computer based on information it gets from the maf and the o2 for the most part. The other sensors do play a role. If either of these sensors the computer relies on is lying to the computer because they are lazy, old, or dirty. Then the computer is making decisions to control fuel based on false information. If you were making decisions based on false information your results would be like the computers results......bad

This usually happens to be a lean condition.

Last edited by glhx; 02-19-2013 at 01:57 PM.
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