Misfire cylinder 1

[Steeler]

New this winter coils and plugs.

Swapped the coil and then the plug. Misfire did not move cylinders.

Misfire is very pronounced around 4500rpm, very abrupt stumble but then clears up and pulls hard to 6500rpm.

What else to check?

[inTgr8r]

Any other codes?

[Steeler]

Just checked as I had an SES light on after drive today.

The misfire has been an ongoing code for a while.

Other codes are SAP and post cat sensor which I know about.
Throttle adaptation and fuel trim on both banks are also on the list.

I am expecting a new tune file any day now but the misfire was a concern having not had that code before.

[inTgr8r]

You've already checked the basics..... Not sure on this one.

SAP and secondary O2s are no problem.

[pokeybritches]

You can pull the plug and see if it's running lean or rich. Another possibility would be the fuel injector. Fuel, air, spark, timing. Timing can be influenced by sensors (appropriate output), ignition timing, Vanos, etc.

[Steeler]

Originally Posted by pokeybritches

You can pull the plug and see if it's running lean or rich. Another possibility would be the fuel injector. Fuel, air, spark, timing. Timing can be influenced by sensors (appropriate output), ignition timing, Vanos, etc.

Plugs are all the same color and appear to be fine, not wet, sooty or burnt.

Injectors are something I had not considered as they are 3 years old and only 4k miles but worth looking into. How to test injectors??

The updated tune should hopefully address fuel, spark, timing etc.

Vanos is rebuilt.
Sensors pre cat are new. Should they be "free air" calibrated as you need to do for a wideband sensor for an AFR gauge???

[GuidoK]

Testing injectors can be done with just a power source and pressurized fuel.
Although if your code only gets up at a certain rpm level, that will be hard to test as that would indicate that it is an injector yeald problem. (for that you need a stable pressurized fuel source and measure how much fuel is squirted out in a minute.
But cleaning them is a good idea.
Lots of video's on youtube. With so low mileage in 3 years, there might be fuel in there all gummed up. Do you use a fuel stabilizer?

Lambda sensors dont have to be free air calibrated. Even a wideband theoretically should not have to be calibrated (regardless if some meters do have that function)

Strange problem. You only get that code around 4500rpm?
HAve you read your code with INPA/DIS/ISTA or with a generic codereader?
The bmw software reads deeper codes (and sometimes gives a clue in the code description), so more than just the P codes.

[Steeler]

Originally Posted by GuidoK

Testing injectors can be done with just a power source and pressurized fuel.
Although if your code only gets up at a certain rpm level, that will be hard to test as that would indicate that it is an injector yeald problem. (for that you need a stable pressurized fuel source and measure how much fuel is squirted out in a minute.
But cleaning them is a good idea.
Lots of video's on youtube. With so low mileage in 3 years, there might be fuel in there all gummed up. Do you use a fuel stabilizer?

Lambda sensors dont have to be free air calibrated. Even a wideband theoretically should not have to be calibrated (regardless if some meters do have that function)

Strange problem. You only get that code around 4500rpm?
HAve you read your code with INPA/DIS/ISTA or with a generic codereader?
The bmw software reads deeper codes (and sometimes gives a clue in the code description), so more than just the P codes.

Thanks Guido,

Have not used a fuel stabilizer no. Should give it a try.

Followed the Innovate instructions for free air calibration just to eliminate any possibility of a bad reading from the sensor when I was having erratic AFR readings.

Yes if I stay below 4-4500 rpm the misfire does not code. I took it easy last night after resetting codes and the misfire did not code.

Using the data logging program to read codes it is fairly comprehensive in its reporting. If I new how to interpret the data I might be able to figure it out.

In any case my tuner has promised an update soon