E46 Fanatics Forum banner
1 - 20 of 52 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter · #1 · (Edited)
-SOLVED-
The issue was an extra o-ring in the crankshaft position sensor slot. This problem was persistent when I bought the vehicle and one of the first things I did was replace the crank sensor, but the one I pulled out had an o-ring on it so I didn't think to search for an o-ring that was stuck in the sensor slot before installing the new sensor. 2.5 years later and I finally found the issue. Now she runs like new and I know the SULEV swap was 100% successful! Cheers to you Fanatics!


-----------


Yes, another one. This may be as simple as a malfunctioning MAF sensor or as difficult as a burned-out valve. If anybody is a GOD at interpreting data, I ask for your input here. To be direct, I believe it to be a failing MAF as I have noticed odd behavior in its reporting, such as sudden spikes and huge intake numbers (up to 60g/s at times). Confusingly, the vehicle idles very smoothly (3.3g/s warm) and the problem does not desist when the MAF is unplugged and the engine is running on the fixed fuel map. I have invested considerable time into this; I have closely read jfoj's cold weather misfire guide and performed nearly all of the work suggested in that thread. I have also completed nearly all of my originally planned engine restoration projects with the exception of the belts, pulleys, and tensioner yet the problem persists. Fortunately, there is a narrow margin of remaining possibilities and, with some help from the crew at e46fanatics, I am confident this discussion will come to a conclusive rest.

I'll do my best to be thorough & succinct. If you need any additional information on anything I write here go ahead and let me know and I'll get it for you. I have a large amount of stored diagnostic data but can always grab more. I have read hundreds of threads from a dozen different forums and found little useful information or actual data. Therefore I have created this thread in an effort to solve this issue and create information to be accessed by people whose paths bring them along this crossroads.

Vehicle: 2003 325ci m56b25 automatic with 230k on odo. Several systems on the vehicle have been reconstructed, which I will elaborate more on later. Not much of the systems that originally made this vehicle a super-low emissions vehicle (SULEV) remain. These systems have been replaced with compatible or equivalent systems from m54 coupe.

A couple of important things to note:
1. m56 stainless steel fuel system has been replaced with 5 bar fuel system from e46 M3 (-rail & injectors).
2. fuel pressure test valve has been installed at the fuel rail and measures steady 70psi (5 bars) at idle and speed.

The engine can experience jerking and misfires at any rpm. This has been persistent through all the repairs over the past 2 years I have owned the vehicle. These symptoms are extremely rare at idle, but when the rpm begins to rise past 2k the engine noticeably hesitates and loses power. Often, the battery light will flicker on and off again during these engine palpitations. The faster the engine goes, the worse the problem becomes. The engine will totally fail to rise past 5k rpm, and I daren't force it to. If I press the accelerator to the kick-down position, the engine jerks back and forth massively and I experience total power failure.

At highway speeds of 80 mph and an engine rpm of about 2.5k, I notice the engine misfire once or twice every minute. At speeds under 60mph and rpm under 2.5k, the symptoms do not manifest often and the car is perfectly fine to drive around town. These issues are very easy to manage by maintaining a low engine speed, and the car has been daily driven in this condition for at least 2 years. Perhaps unrelated, the engine often requires 2 cranks to start. These problems are especially prevalent while the engine is still cold, and are far worse. The engine starts to experience these problems less and regain a fair bit of power once the engine is warm.

Here I will briefly go over the notable work I have done on the engine.
1. Rebuilt the entire evap system.
2. SAP & Post-Cat 02 delete w/ ms54.1 euro tune.
3. Super Sprint headers & backpressure test.
4. ECU electrical repair.
5. Vanos seals & rings; solenoids checked.
6. Disa valve & O-ring.
7. All intake vacuum hoses have been plugged.
8. New CCV cap & diaphragm.
9. All hoses checked for cracks and seal.
10. New coolant thermostat & ambient air temp sensor.
11. Valve cover gasket replaced.
12. New spark plugs; coils swapped.
13. Compression test; cyl 1-5 170psi, cyl. 6 160psi .
14. ICV and throttle body tested to function.
15. 5 bar fuel pump & fuel pressure reg., fuel filter, plastic fuel tank (M3).

CEL is not on. Codes read misfire in all bank 2 cylinders. Engine idles smoothly with no issues. A few small things to note: The problem is very bad when the engine is cold but subsides significantly after being driven for a few minutes; idle to temp doesn't seem to do much. What's more, easing slowly off the pedal after kicking down reduces the effect. As noted earlier, compression and fuel pressure seem a-ok.

Below is some of the data I've compiled based on the document in this thread here. I have done my best to gather the data in the manner requested. I have mountains of this stuff, so please feel free to ask for any data comparisons or custom data charts you wish. The data is in ~5 min. intervals and goes as follows: cold start, steady highway speed, and warm idle, followed by a diagnostic report w/ freeze frame. I have also included some data comparisons that I think may prove useful. Lastly, I have a short video of the problems themselves as they manifest on the dash in my car. Hopefully, the information here will provide some much-needed support to a struggling e46 and its owner, and help bring this issue to a conclusive end for everybody. Thank you.

CSV not allowed here. Here's a link to the Dropbox Folder!
 

·
Registered
Joined
·
6,809 Posts
Look at the ignition timing here ------------------------------------------------------------------------------|
..................................................................................................................................................................................................................|
.................................................................................................................................................................................................................V
It jumped from 25* to -10.5 then to 31.5* degrees in just a few seconds while car at 56 mph and rpm=1915. What's going on?


58.40889
258611.0411.37255400.4200.4251.0755521.08043214.3
253250.025220197.64.68754.6875-0.78125-1.5625224358.40889258611.0411.37255400.4200.4251.0755521.08043214.3
254251.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
255252.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
256253.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
257254.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
258255.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
259256.0261116.86275197.600-0.78125-1.5625191556.5447808610.8810.19608400.4200.420.9799040.97307214.3
260257.026110197.600-0.78125-0.78125175154.05929-10.5866.510.19608400.4200.421.9978721.99787214.3
261258.026110197.600-0.78125-0.78125175154.05929-10.5866.510.19608400.4200.421.9978721.99787214.3
262259.026110197.6000-0.78125173654.0592931.5866.5610.19608400.4200.421.9978721.99787214.3
263260.026110197.6000
 

·
Premium Member
E30M3 Race F10 535 R1150Rt M Coupe
Joined
·
8,332 Posts
On vacation, is the timing varying (impossible to read on my phone) that much?

If so, we need to look at what parameters do such.
Any knock sensing events at that time? Super rich to lean or vice versa?
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #11 · (Edited)
@<sixtyseconds what did you do for a fuel supply line to the rail?
Ok, bear with me. Starting from the fuel tank; I used the nylon tubing that came with the original m3 fuel tank up to the fuel filter, then 5/16 SAE fuel line (120psi, high-grade) connecting the nylon tubing and the fuel filter quick connect. Coming off the fuel pressure regulator, the same fuel line heading towards the fuel rail. I cut the original stainless steel fitting that connects the steel fuel pipe to the fuel rail and installed a 5/16 DIN Compression Fitting to 1/4 NPT at the point where I cut the steel tubing.

Then I connected a 1/4 NPT to 5/16 barb fitting and used that to connect my rubber fuel line. I also installed this fuel pressure adapter between the rail and the original fitting for a bit of convenience, but if you go this route make sure you cut the original steel tubing coming from the rail just before the bend, so it's as straight as possible. You won't have any fitment issues going this route. Bear in mind, the evaporative emissions system is a whole separate bag of worms and is just as difficult as the fuel system.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #12 ·
On vacation, is the timing varying (impossible to read on my phone) that much?

If so, we need to look at what parameters do such.
Any knock sensing events at that time? Super rich to lean or vice versa?
Yes, my friend. I am not particularly good at interpreting the ignition timing data, but it would seem to correspond with my fuel trims swinging wildly back and forth between very rich and very lean. Some of that data is posted; I will try and log a comparison between ignition timing and fuel trims and post that for you later today.
 

·
Registered
2000 E46 323i, 3.0L and 2.0L Z3's
Joined
·
1,280 Posts
I noticed in your video that the battery light was coming on when you were having the problem. Can't make up my mind if this is a symptom of the cause or a result of the issue. I'm leaning towards it being a symptom of the problem because the alternator will still be spinning and charging until the engine stops. Your "D- Fault" log also shows the battery voltage dropping (14.3V to 12.7V worst case) when ever you have the problem.

Check:
  • Battery connections
  • Tightness of the "Positive" jump start bolt
  • Alternator connections, the big cables.
  • Any and all bolted fuses and the main supply leads to the fuse supply rails.

Your "B- Highway" and "D- Fault" logs both show the MAF values lower than expected for the 2.5L engine at those steady speeds. If you had an under reporting MAF, there should be corresponding high lean total fuel trims. You don't have high lean total fuel trims.

I noted with interest, that you have fitted the M3 fuel rail and injectors with 5 bar fuel pressure. The M3 with the S54B32 engine will have larger injectors than you car. Having them in your car without any DME changes will cause more fuel to be injected than expected. Did you scale the DME to the injectors or other similar change to compensate for the extra fuel being injected? Just looking for a possible extra fuel offset to balance the under reporting MAF idea.
 

·
Registered
Joined
·
6,809 Posts
I noticed in your video that the battery light was coming on when you were having the problem. Can't make up my mind if this is a symptom of the cause or a result of the issue. I'm leaning towards it being a symptom of the problem
Agreed. OP should fix battery light flashing while engine at around 2000 rpm. with this sort of voltage spike noise applied to the DME, it could cause the computer going crazy (affect injector pulses, igniton timing, ended up with bucking engine).
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #15 ·
I noticed in your video that the battery light was coming on when you were having the problem. Can't make up my mind if this is a symptom of the cause or a result of the issue. I'm leaning towards it being a symptom of the problem because the alternator will still be spinning and charging until the engine stops. Your "D- Fault" log also shows the battery voltage dropping (14.3V to 12.7V worst case) when ever you have the problem.

Check:
  • Battery connections
  • Tightness of the "Positive" jump start bolt
  • Alternator connections, the big cables.
  • Any and all bolted fuses and the main supply leads to the fuse supply rails.

Your "B- Highway" and "D- Fault" logs both show the MAF values lower than expected for the 2.5L engine at those steady speeds. If you had an under reporting MAF, there should be corresponding high lean total fuel trims. You don't have high lean total fuel trims.

I noted with interest, that you have fitted the M3 fuel rail and injectors with 5 bar fuel pressure. The M3 with the S54B32 engine will have larger injectors than you car. Having them in your car without any DME changes will cause more fuel to be injected than expected. Did you scale the DME to the injectors or other similar change to compensate for the extra fuel being injected? Just looking for a possible extra fuel offset to balance the under reporting MAF idea.
I am almost positive the battery light coming on is a symptom of the problem because it doesn't always come on when the problem occurs. I attribute this to the engine fractionally stalling at speed. This would also explain the voltage drop as the circuit switches from the alternator to the battery when the engine stalls. I will double-check these connections regardless.

The fuel rail and fuel injectors are original to the m56 fuel system. I did not swap these components out with m3 variants. Also, the m56 has a slightly larger diameter throttle body than the m54. Maybe this could explain the MAF value discrepancy?
 

·
Registered
2000 E46 323i, 3.0L and 2.0L Z3's
Joined
·
1,280 Posts
Have a look at the voltage in your D-Fault log. It moves around too much. You'll know when the problem occurred in the log. Do they correspond to when the Voltage was moving?

With your car stationary, rev it a bit. The battery light does not come on when the rev's drop. The battery voltage des not move around. Turn the engine off. The battery light comes on just as the engine stops rotating. Your battery light coming on when there are good rev's on the engine is not normal.

I have 3 BMW's, with 2.0L 2.5L and 3.0L engines. They all use roughly the same amount of air mass at the same speed in cruise conditions. This makes sense as the car needs to be producing a certain amount of energy to keep the car at that cruise speed. The speed is the same, so the amount of energy required is roughly the same allowing for the air coefficient of the car and its weight. The 3.0L engine has a bigger MAF and throttle body to the others, yet it is using roughly the same amount of air as the others. Your E46 is between 20% and 25% low on MAF readings at the cruise speeds in your logs. Don't know why, its just an observation.
 

·
Premium Member
2003 330cic, 2003 325iT
Joined
·
7,593 Posts
@NZ00Z3 for reference (you may know this) the M56 uses a modified 330 intake and 5 bar injectors/filter/pump. The throttle body and MAF are 330, even though the engine is a b25.
 

·
Premium Member
2003 330cic, 2003 325iT
Joined
·
7,593 Posts
Ok, bear with me. Starting from the fuel tank; I used the nylon tubing that came with the original m3 fuel tank up to the fuel filter, then 5/16 SAE fuel line (120psi, high-grade) connecting the nylon tubing and the fuel filter quick connect. Coming off the fuel pressure regulator, the same fuel line heading towards the fuel rail. I cut the original stainless steel fitting that connects the steel fuel pipe to the fuel rail and installed a 5/16 DIN Compression Fitting to 1/4 NPT at the point where I cut the steel tubing.

Then I connected a 1/4 NPT to 5/16 barb fitting and used that to connect my rubber fuel line. I also installed this fuel pressure adapter between the rail and the original fitting for a bit of convenience, but if you go this route make sure you cut the original steel tubing coming from the rail just before the bend, so it's as straight as possible. You won't have any fitment issues going this route. Bear in mind, the evaporative emissions system is a whole separate bag of worms and is just as difficult as the fuel system. Let me know if you have any more questions.
This is great. Clarification - if you used the M3 supply and return lines, and the m3 filter, why did you need to modify the lines from the tank - I would have thought they would snap fit as they were intended to match.

Also, I understand why you modified the line to the rail, but I am a bit confused that you needed to put in the fuel pressure adaptor, as the M3 fpr has a Shrader adapter.
 

·
Registered
Joined
·
30 Posts
Discussion Starter · #20 · (Edited)
This is great. Clarification - if you used the M3 supply and return lines, and the m3 filter, why did you need to modify the lines from the tank - I would have thought they would snap fit as they were intended to match.

Also, I understand why you modified the line to the rail, but I am a bit confused that you needed to put in the fuel pressure adaptor, as the M3 fpr has a Shrader adapter.
Great questions! It took me an entire day to remember why I had to modify the fuel feed line in the first place! The fuel tank actually came out of an M3 Convertible so the fuel feed line was slightly longer than the coupe variant. I had to cut the line down past the bump to shorten it so I installed a compression fitting where the hose bump should have been. I imagine the tank from a coupe would have been plug and play with no modification. Side note: the feed and return lines do not plug into their respective fuel filter and fpr directly. Both of them will require hoses.


As for the fuel pressure adapter, there were a couple of reasons I decided to put it on the rail. First off, from what I understand the valve on the fpr tests the fuel pressure before it is cycled to the return line. This means it can only tell what the fuel pressure is from the pump through the filter but does not confirm it is doing its own job. Placing it as close to the rail as possible confirms to me that the pump, filter, and fpr are all being tested for pressure and the system is functioning as close to the rail as possible. Secondly, it is far more convenient to have the test valve right at the top of the engine. This makes it easier to test my fuel pressure or install a fuel pressure gauge into the cabin, which is something I have been seriously considering.

Here's some pictures!
 
1 - 20 of 52 Posts
Top