PicoScope 7 Automotive
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2013 BMW 328i (F30 N26) Misfire
2013 BMW 328i (F30 N26) Misfire
I’ve got 140010 and 140410 codes for several cylinders misfiring and cylinder 4 misfire. You can clearly hear and feel the miss and it practically stalls about a minute after cold startup.
Immediately preceding these errors I had installed an Evolution Racewerks Charge Pipe, but I’ve never had a tune on the car. The install went relatively smoothly, and I test drove it without issue for a couple miles before the misfire started.
Things I've tried/ruled out:
I thought maybe it’s the meth bungs leaking in the aftermarket charge pipe that I forgot to silicone tape. So I sealed those up good. No dice.
I swapped back to the stock charge pipe. No dice. Wound up getting a proper smoke machine and didn't find any leaks on the intake - throttle body path. I've replaced all 4 spark plugs and injectors with no luck. Compression tested out fine. Dealership looked at it and wanted to replace the DME. At $2600 USD I said thanks but no thanks and got a used DME from precisionecu.com. That did not work. Same exact symptoms. The harness going to the injectors has good continuity.
So here I am, a new Pico 2204a owner and I got my own reading of the injector voltage pulses after a cold start. Can anyone shed any light on if the injector waveforms attached look normal? Am I even reading these correctly? This is at idle, after the codes were cleared, only 10-20 seconds after cold start.
What else could I look at with this scope to further troubleshoot this issue?
Immediately preceding these errors I had installed an Evolution Racewerks Charge Pipe, but I’ve never had a tune on the car. The install went relatively smoothly, and I test drove it without issue for a couple miles before the misfire started.
Things I've tried/ruled out:
I thought maybe it’s the meth bungs leaking in the aftermarket charge pipe that I forgot to silicone tape. So I sealed those up good. No dice.
I swapped back to the stock charge pipe. No dice. Wound up getting a proper smoke machine and didn't find any leaks on the intake - throttle body path. I've replaced all 4 spark plugs and injectors with no luck. Compression tested out fine. Dealership looked at it and wanted to replace the DME. At $2600 USD I said thanks but no thanks and got a used DME from precisionecu.com. That did not work. Same exact symptoms. The harness going to the injectors has good continuity.
So here I am, a new Pico 2204a owner and I got my own reading of the injector voltage pulses after a cold start. Can anyone shed any light on if the injector waveforms attached look normal? Am I even reading these correctly? This is at idle, after the codes were cleared, only 10-20 seconds after cold start.
What else could I look at with this scope to further troubleshoot this issue?
- Attachments
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- cyl 1.psdata
- (57.06 KiB) Downloaded 373 times
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- cyl 4.psdata
- (58.52 KiB) Downloaded 350 times
Re: 2013 BMW 328i (F30 N26) Misfire
Problem solved. This was a real boneheaded mistake on my part. 
While replacing the charge pipe one of the engine vanity cover mounting grommets must have fallen down inside the charge pipe and then got sucked into the #4 intake runner. I had noticed this piece was missing, but not until after the first shop had looked at the car and I had assumed that they misplaced it.
To turn this back around to oscilloscope diagnosis...I wonder if this sort of obstruction would manifest in any sensor readings? Maybe increased current draw from the starter on the intake stroke of cyl 4?
While replacing the charge pipe one of the engine vanity cover mounting grommets must have fallen down inside the charge pipe and then got sucked into the #4 intake runner. I had noticed this piece was missing, but not until after the first shop had looked at the car and I had assumed that they misplaced it.To turn this back around to oscilloscope diagnosis...I wonder if this sort of obstruction would manifest in any sensor readings? Maybe increased current draw from the starter on the intake stroke of cyl 4?
- Attachments
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leonardorj
- OneWave
- Posts: 27
- Joined: Tue Mar 24, 2020 1:32 pm
Re: 2013 BMW 328i (F30 N26) Misfire
Caramba este pedaço é da junta da admissão ?
Que bom que resolveu seu problema.
Que bom que resolveu seu problema.
Re: 2013 BMW 328i (F30 N26) Misfire
I believe an RC test or an in cylinder would have shown this issue also a intake pulse waveform. Sorry about your luck that can be so frustrating.
Re: 2013 BMW 328i (F30 N26) Misfire
But thanks for posting the solution!
In cylinder probably would have spotted it, possibly exhaust pulse too, though that would have shown an anomaly on #4 and taken quite some experience to spot it was restricted intake.
Intake pressure pulse sense would have shown it. Don't think a relative compression would show enough detail.
In cylinder probably would have spotted it, possibly exhaust pulse too, though that would have shown an anomaly on #4 and taken quite some experience to spot it was restricted intake.
Intake pressure pulse sense would have shown it. Don't think a relative compression would show enough detail.