S50B32 Euro not running clean.

[M3 euro ltw]

Low rpm loss of power

PM sent

[Dissembler]

does your motor have vanos? I've been told by a couple of people that the ECU relies on road speed signal compared against load/rpm charts to determine what it does with the vanos, which is how these motors make so much torque. If your not getting/have an erratic speed signal at all, could explain your problems. Or vanos could just not be working

[Mr. Horsepower]

I'm having speedometer signal yes, as well as vanos.

[M3 euro ltw]

update

Let us know if my suggestions panned out.......

[Mr. Horsepower]

Yes, but don't think I have any possibility to get such test done. But I will search around and hear if anyone can do it.

It's a small country and not so many specialists here.

[Mr. Horsepower]

Just had to try something not healthy today....
On cold engine I did floor it in first and the rear tires started to spin and it pulled like hell!
That means that it works when it is cold...

Does not that cook it down to the O2 sensors?

[Mr. Horsepower]

Did a test yesterday as well. Disconnected these sensors;
-Water temp ECU
-Intake temp
-MAF

And there was no difference in the way the engine acted. I did this on cold and hot engine.

Going to disconnect the O2 sensors today to see if there is any difference. I got told that the engine is not using O2 sensor signal when the engine is cold. So might have my problem in them.

If you have a healthy engine and disconnect a O2 sensor, there shall be a notice in the way the engine act right?

[Mr. Horsepower]

Still have not figured this problem out...

Pulled the spark plugs today, all looked the same. Even after driving a while.



Here is the same plug compared to one I pulled from the engine last year



Film where you can hear the problem, if the car had been cold in this video the tires would have screamed.

[Wanganstyle]

get AFR meter; you can get inexpensive - cost less than 3 runs at the dyno (here at least)

I had problems with over rich fueling on my S54 on initial tuning, the motor would not make power untill above 6,000 where the vanos cam setting opened up for high rpm and then the car would drive ok.

if afr is off, then we will know.

DME does not pay attention to O2 sensors when throtltle is 100%, its just watching knock sensors to to pull timing if needed to keep it from blowing up!


02's are for trimming fuel other places in the mapping- Alex @ ABL would know the switch points and OEM AFR ratios that the S50b32 should be running

AFR is your basis of what is going on, dyno RWHP is not even as good as the AFR for reading for health and tune check up - you could have a 310rwhp motor dumping 11:1 afr and be making 280 rwhp, your dyno will also be completly different than the next guys!

If have dyno, there should be a emissions guage or meter- can you run a Emissions test on it and see what its doing?

I know in california our smog is really good to check up on engine health- I have caught some misc things out with a simple $45 smog test lol

are you using a 5.0 BAR fuel pressure regulator? and do you have a fuel pressure gauge to see fuel pressure at the rail??

if you have this problem only when hot, it may be a physical wire that is broken, loose, or erratic crank position / cam positon sensor

is there any way you can olliscope the sensors? like if someone w a M3 has a standalone they would be able to pull the olliscope of the sensors with the standalone - BMW actually has published olliscope read out on the sensors on TIS so you could verify EXACTALY what the sensor is doing :)

[Mr. Horsepower]

Thanks for a good answer with a lot of stuff I don't know what is :)

I have had a wideband lambda on the car, but that was on the road. And the AFR was just fine. We used a Innovate LM2 with logging.

The dyno session I was on there was no AFR measuring, just simply pull and get off. We did not have much time.

I have got many tip about the coils, they tend to fail on these engines.

[Wanganstyle]

coils is an often failure- along with the boots.

No matter what car I drive, whenever I go to Laguna seca I fear coil-pack problems. Have had issues on DOHC bmw's and dis subarus more than once there...... every thing bad mechanically rears it ugly head @ Laguna.

If you have a fuel pressure guage you would be able to see if is proper stable 5.0 BAR at the rail

Oliscope = dyno for sensors, if you have electrical engineer friend would be ideal to help with this- an EE taught me about olliscope-

[Mr. Horsepower]

But when you test a sensor with oscilloscope, don't you need to have the sensor on the car and the car running or what?
How about what nubers or curves that the read out comes with?

[Mr. Horsepower]

Checked the fuel pressure.

With vacuum:



Without vacuum:

[lexx]

coils is an often failure- along with the boots.

No matter what car I drive, whenever I go to Laguna seca I fear coil-pack problems. Have had issues on DOHC bmw's and dis subarus more than once there...... every thing bad mechanically rears it ugly head @ Laguna.
-

I had one bad spark plug boot on my m50 and I thought my motor was gonna quit. It idled well but had horrible hesitation and power loss...very frustrating.

[Wanganstyle]

But when you test a sensor with oscilloscope, don't you need to have the sensor on the car and the car running or what?
How about what nubers or curves that the read out comes with?

osciloscope will be able to dyno the sensor readings without it running, it will be a wave pattern of signal / pauses; if you hook up the meter and crank engine it should be able to read-out the graph.

do you have any BMW or MB tech friends? They should have a tool for this somewhere in dealershi- I have only done oscilloscope with standalone aftermarket DME; it had oscilloscope function built in.

seems like your fuel pressure is working ok -I'm guessing b32 is a 5 bar system like the S54? 5 bar is > 70 psi, and yours is reacting to vacuum correctly it seems