Well if it comforts you I had major issues with misfires on cylinder 1,2,3. I was using new plugs and Eldor coils as well. What fixed it for me was switching to B58 coils.
E9X N55E Speedtech 6266 Build
- Thread starter sk8
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@houtan Thanks for the info. I have the second fuel pump setup on a separate relay. I have tested with it unplugged to to see if maybe the power draw of it kicking on was causing voltage to drop or something, but that had no effect on the misfires. Here's a diagram of how it's wired in on my car.
I have also used ISTA-D to do injector tests, which all passed. I think that test doesn't guarantee that the injectors are good, but I tests for leaks. I'll try to dig around in the software to see if there's any other diagnostics for it.
When I was taking the stock turbo manifold off I noticed cyl 6 having a little more carbon buildup compared to the rest. Even though I don't think I ever got a cyl 6 misfire, I'll probably swap out cyl 6 injector when I do the b58 coils. I have an extra injector laying around since I bough 3.
@SLOWESTN54 I'm really hoping that's my issue. The coils should be here Wednesday, not sure when the NXM kit will come though, don't have tracking yet. I'll be trying pump gas if I still have misfires with the 58 coils.
I have also used ISTA-D to do injector tests, which all passed. I think that test doesn't guarantee that the injectors are good, but I tests for leaks. I'll try to dig around in the software to see if there's any other diagnostics for it.
When I was taking the stock turbo manifold off I noticed cyl 6 having a little more carbon buildup compared to the rest. Even though I don't think I ever got a cyl 6 misfire, I'll probably swap out cyl 6 injector when I do the b58 coils. I have an extra injector laying around since I bough 3.
@SLOWESTN54 I'm really hoping that's my issue. The coils should be here Wednesday, not sure when the NXM kit will come though, don't have tracking yet. I'll be trying pump gas if I still have misfires with the 58 coils.
Hey sk8, 135 DCT with dual lpfp reflex+ setup here. You need a solid state relay to control the second lpfp instead of the hobbswitch. I'm almost certain that the hobbswitch is your issue here. Also I highly recommend you update your DMFW to the S55 one, even on lower RPM it could still throw misfires.
I went with the NOS solid state relay fyi, Get those two things situated and report back.
Got the b58 coil kit in today, and that seemed to fix my misfires, at least in low boost. Plugs are SILZKBR8F8S gapped to 0.026".
Here's a log of a 60-130 run.
I ended up turning the boost up a bit after this run and ran into DSC issues. Had DSC off (short press of the button), and when I did a pull I got codes cc-id 24, 354, and 672. I don't think I was spinning, since it happened when I was in 4th gear ~70mph. Going to make sure I turn DSC fully off for the next runs so I don't run into this issue. Here's a log from when I got the errors.
@onedirty5 Not sure if I'm understanding why the second fuel pump relay would be the issue, do you have any info on why it is a problem?
Here's a log of a 60-130 run.
I ended up turning the boost up a bit after this run and ran into DSC issues. Had DSC off (short press of the button), and when I did a pull I got codes cc-id 24, 354, and 672. I don't think I was spinning, since it happened when I was in 4th gear ~70mph. Going to make sure I turn DSC fully off for the next runs so I don't run into this issue. Here's a log from when I got the errors.
@onedirty5 Not sure if I'm understanding why the second fuel pump relay would be the issue, do you have any info on why it is a problem?
I had issues with reflex+ operating correctly, and couldn't get it to work with the hobbswitch. But now that I come to think of it, it came down to figuring out the correct settings for both the reflex pi tune & dme tune. At that point I was already using a solid state relay.
So if you want to take advantage of pwm capability of the reflex+ unit you purchased/ have the reflex+ control the 2nd lpfp, a solid state relay is recommended.
So if you want to take advantage of pwm capability of the reflex+ unit you purchased/ have the reflex+ control the 2nd lpfp, a solid state relay is recommended.
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Sweet build dude! Look forward to seeing how it turns out when you get it going smooth! Jelly of your E85 access haha
I'm also bamboozled seeing a 135 with a piston style hpfp. Was your car EWG?
I'm also bamboozled seeing a 135 with a piston style hpfp. Was your car EWG?
@onedirty5 Ah that makes sense, a mechanical relay would not work well with PWM. I think you can set it up to be an on/off thing with the RFX and still use a mechanical relay. If you are using a RFX to control the fuel pump, you don't need a hobs switch at all, just one wire running to the RFX. This is what I see in their documentation.
I have a pressure sensor logging my LPF, and not seeing spikes when the second fuel pump kicks on, so probably going to stick with the hobs switch setup until it causes problems.
@azshantris Looks like BMW switched to the piston style in 2013, car is still PWG. Really wish I had the old style, would have been a cheaper HPFP upgrade. I've been keeping up with your build, thanks for posting it!
I have a pressure sensor logging my LPF, and not seeing spikes when the second fuel pump kicks on, so probably going to stick with the hobs switch setup until it causes problems.
@azshantris Looks like BMW switched to the piston style in 2013, car is still PWG. Really wish I had the old style, would have been a cheaper HPFP upgrade. I've been keeping up with your build, thanks for posting it!
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It's been a while since I posted an update. The b58 coils cleared up my misfires until 18psi, anything more and the car still wanted to misfire.
Here's an 18psi log that was clean.
I ended up gapping the plugs down from 0.026" to 0.020" and that gave me a little more room, but I started having misfires at ~6k rpm. The next day out the car wanted to misfire when spooling again, even with the boost back down to 18psi. I pulled the plugs and found this on 4 out of 6 spark plugs.
I could feel the grove in the ceramic with my fingernail, so I ended up throwing the NGK 97506 I had laying around gapped at 0.018" with a ton of dielectric grease. Which finally let me get a lot closer to the 26psi goal.
Here's a run where I hit a misfire [email protected] rpm in 5th gear. I'm guessing this one is flywheel related, because it felt clean the whole way up.
Here's another run with a bit more boost ~25psi, I'm letting off early to avoid the misfire.
At this point I'm trying to source a s55 flywheel since I'm still on the stock DCT flywheel. Will report back once I get that installed.
Here's an 18psi log that was clean.
I ended up gapping the plugs down from 0.026" to 0.020" and that gave me a little more room, but I started having misfires at ~6k rpm. The next day out the car wanted to misfire when spooling again, even with the boost back down to 18psi. I pulled the plugs and found this on 4 out of 6 spark plugs.
I could feel the grove in the ceramic with my fingernail, so I ended up throwing the NGK 97506 I had laying around gapped at 0.018" with a ton of dielectric grease. Which finally let me get a lot closer to the 26psi goal.
Here's a run where I hit a misfire [email protected] rpm in 5th gear. I'm guessing this one is flywheel related, because it felt clean the whole way up.
Here's another run with a bit more boost ~25psi, I'm letting off early to avoid the misfire.
At this point I'm trying to source a s55 flywheel since I'm still on the stock DCT flywheel. Will report back once I get that installed.
I was running NGK SILZKBR8F8S which was recommended by my tuner for e85. So while it's different then what a lot of people run, I wouldn't say it's wrong. Most people run the NGK 97506 (SILZKBR8D8S), which is what I have in the car now that I ruined the last plugs.
These are the correct 2 step colder Plugs for b58 coils. If you look they have different tips where the coils go. Iām not saying itās the reason your having issues, but having incorrect plugs doesnāt help.
Sorry it took me a bit to get the right part number had to search through my orders.
Sorry it took me a bit to get the right part number had to search through my orders.
Ah, didn't know that, thanks for linking the part number. I need to go check out the coil boots that came with the NXM coil kit and compare it to the boot on the OEM b58 coil. Assuming the insides that touch the plug look the same, I might order a set of these as backup.
That is some good information right there! I would have been in the exact same boat as @sk8 (i had no idea the plugs had different tops) and after seeing you were having misfire issues with yours and the B58 kit fixed the issue I was just going to buy it for a preventative measure. Update us when you get the new plugs! If it works I will buy the same combo.
My cars been super happy after the b58 coils. Now at 29.5 psi no missfires. Happy to help
@SLOWESTN54 question I am going to buy the B58 coil kit and the plugs you linked, but I have not researched what coils people usually go with. They have Bosch, Dinan and Bavarian Autosport. Which coil did you go with? I figure if you are pushing damn near 30 PSI with no problems, I will just go with the same set you have.
I went with the factory Eldors. Didnāt wanna mess around with non Oem options.
It's been a while since I posted an update. Got a flywheel from a 2020 M2 Comp put on the car. That helped clear things up a lot.
I was able to get some clean runs in with no missfires at ~22psi.
Still unable to hit my 26 psi goal, anything more seems to misfire on cyl 6 again. Not sure where to go from here.
I was able to get some clean runs in with no missfires at ~22psi.
Still unable to hit my 26 psi goal, anything more seems to misfire on cyl 6 again. Not sure where to go from here.
It feels pretty fast, spins 3rd gear but doesn't feel crazy compared to my boosted e30. It's definitely faster than the e30 though.
I'm using e85, but ethanol sensor shows it's at ~73% ethanol. Seems like I can hit 26psi spooling up and as long as I taper the boost down to 22psi@6k rpm I can avoid misfires for now.
Really happy I'm having Chris tune it because he's been super helpful in troubleshooting the issues. We're on like the 13th tune revision with ~60 emails back and forth now. I might get the chance to get a few runs in on a dyno this weekend.
I haven't worked with a tuner yet, but everybody I've seen mention working with Chris at Motiv on the forums it's always been really positive. Here's another check in the plus column
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