[Zmatthews01]

Hi guys new here trying to figure out why my car is pulling these codes, my car will run fine at idle but when I accelerate between 2-4k RPM it begins to misfire and go into limp mode. I have installed brand new DME, NGK iridium plugs, Bosch coils, Boost solenoids, vanos solenoids, walnut blasted the valves, new index 12 injectors installed by bmw and tested, new Stage 2 LPFP with regulator, new fuel sensors, new boost sensors, and new MAF. The car has an aftermarket DP, Evolution racewerks Charge pipe with Tial BOV as well.

I have a data log below which I have zero clue how to read but maybe someone else can see something I don’t?

https://datazap.me/u/zmatthews01/200...og=0&data=3-20

[konstat]

Originally Posted by Zmatthews01

Hi guys new here trying to figure out why my car is pulling these codes, my car will run fine at idle but when I accelerate between 2-4k RPM it begins to misfire and go into limp mode. I have installed brand new DME, NGK iridium plugs, Bosch coils, Boost solenoids, vanos solenoids, walnut blasted the valves, new index 12 injectors installed by bmw and tested, new Stage 2 LPFP with regulator, new fuel sensors, new boost sensors, and new MAF. The car has an aftermarket DP, Evolution racewerks Charge pipe with Tial BOV as well.

I have a data log below which I have zero clue how to read but maybe someone else can see something I don’t?

https://datazap.me/u/zmatthews01/200...og=0&data=3-20

Check around on google, this thread has a lot of good info:
https://www.e90post.com/forums/showthread.php?t=1917374

It ended up being the injectors for them, even though they already had index 12s. They replaced with new index 12s and it solved their issue.

From your log your bank 1 AFR is very lean, which is what the code is also saying. To rule out injectors, swap bank 1 injectors to bank 2 and see if it follows. If it doesn’t then it’s possibly a bad primary O2 sensor on bank 1. Check the bank 1 O2 voltage if you’re able to

[Zmatthews01]

**New update**, I tracked the O2 sensor wire and there was a nick in it that I fixed now it’s just misfire cylinder 1 code. I have noticed my fuel injector 1 is vibrating heavily when I WOT. And there is smoke coming from the seal, is this a problem with the injector or the bore of the cylinder? What could be the issue here causing this misfire. I did change out injectors and the code stayed on cylinder 1

[Zmatthews01]

Originally Posted by konstat

Check around on google, this thread has a lot of good info:
https://www.e90post.com/forums/showthread.php?t=1917374

It ended up being the injectors for them, even though they already had index 12s. They replaced with new index 12s and it solved their issue.

From your log your bank 1 AFR is very lean, which is what the code is also saying. To rule out injectors, swap bank 1 injectors to bank 2 and see if it follows. If it doesn’t then it’s possibly a bad primary O2 sensor on bank 1. Check the bank 1 O2 voltage if you’re able to

Replied above ^

[konstat]

Originally Posted by Zmatthews01

**New update**, I tracked the O2 sensor wire and there was a nick in it that I fixed now it’s just misfire cylinder 1 code. I have noticed my fuel injector 1 is vibrating heavily when I WOT. And there is smoke coming from the seal, is this a problem with the injector or the bore of the cylinder? What could be the issue here causing this misfire. I did change out injectors and the code stayed on cylinder 1

Curious, how’d you go about fixing the cut in the wire?

If you changed out the injector and the problem is still with cylinder 1 and there’s smoke coming from the injector seal area then I think you have an ovaled fuel injector bore in the head. If your injector rocks in the bore after it’s installed (before installing the line to the fuel rail) then that’s also an indication of an ovaled bore.

If you don’t want to remove the injector again, you could perform a compression check and leak down test in that cylinder to confirm air is flowing out the injector bore

[Zmatthews01]

Originally Posted by konstat

Curious, how’d you go about fixing the cut in the wire?

If you changed out the injector and the problem is still with cylinder 1 and there’s smoke coming from the injector seal area then I think you have an ovaled fuel injector bore in the head. If your injector rocks in the bore after it’s installed (before installing the line to the fuel rail) then that’s also an indication of an ovaled bore.

If you don’t want to remove the injector again, you could perform a compression check and leak down test in that cylinder to confirm air is flowing out the injector bore

This was actually super helpful, I actually already diagnosed it was bored but that was spot on!! I already have the car with the head completly off, it looks like the damage may be done and I’m going to get a new head tomorrow

[Zmatthews01]

Originally Posted by konstat

Curious, how’d you go about fixing the cut in the wire?

If you changed out the injector and the problem is still with cylinder 1 and there’s smoke coming from the injector seal area then I think you have an ovaled fuel injector bore in the head. If your injector rocks in the bore after it’s installed (before installing the line to the fuel rail) then that’s also an indication of an ovaled bore.

If you don’t want to remove the injector again, you could perform a compression check and leak down test in that cylinder to confirm air is flowing out the injector bore

also the wire looked like it got pinched and was severed (brown internal wire) I just did a normal splice and wired it back with a wire connector, and the O2 sensor code was resolved.

[konstat]

Originally Posted by Zmatthews01

This was actually super helpful, I actually already diagnosed it was bored but that was spot on!! I already have the car with the head completly off, it looks like the damage may be done and I’m going to get a new head tomorrow

Nice man! You’re making quick work. Do you think the bmw dealership damaged the injector bore when they did the injector job?

[Zmatthews01]

Originally Posted by konstat

Nice man! You’re making quick work. Do you think the bmw dealership damaged the injector bore when they did the injector job?

I wish but I think not, I was inexperienced at removing them and I wiggled them out with no tool, I most likely did it. You live and you learn

[konstat]

Originally Posted by Zmatthews01

I wish but I think not, I was inexperienced at removing them and I wiggled them out with no tool, I most likely did it. You live and you learn

There’s a repair kit you can buy where you tap threads into the injector bore and then install a threaded part with the correct injector bore size. This would be even easier and less risky with the head off. Kind of pricey but cheaper than a new head.

https://ppifpr.com/ppi-BMW-injector-bore-repair-kit/

[Zmatthews01]

Originally Posted by konstat

There’s a repair kit you can buy where you tap threads into the injector bore and then install a threaded part with the correct injector bore size. This would be even easier and less risky with the head off. Kind of pricey but cheaper than a new head.

https://ppifpr.com/ppi-BMW-injector-bore-repair-kit/

Sorry for the late reply, I went ahead and replaced the head and I wanted to seat new valves, problem was resolved and I started it right up. Only thing I have to say is make sure your head isn’t machined or not cause I had to reorder and tear it all back down because my cylinder was machined and needed a 1.52mm special gasket 😭