Spark Plug Gaps

[JK-M5]

Anyone

[BPMSport]

The stock plugs come with the stock gap.

You should check to see if this is an isolated incident in one cylinder or multiple - then switch the coils and see if the fault moves. If it doesn't, then it could be a faulty injector or hardware problem.

We recommend NGK plugs over the stock ones, especially on higher power applications. You should contact your tuner.. we haven't had any misfire issues with 90% of the cars we've tuned, even with the stock plugs.

[JK-M5]

What unusual mike is there's no fault codes of any sort

[Guy M5]

I seem to remember that you had your car tuned by Evolve around the time the misfire started?

Perhaps changing the coil packs will cure it, fingers crossed.

However, many tuners will go to a slightly colder plug to avoid misfires after tuning and / or reduce the plug gap.

I asked this question of Evolve on your post about the tune and they said their tune did not need this, maybe so but I'd still go back and speak to Evolve about it. Perhaps they could remove the tune and temporarily put it back to stock to rule out the tune as having anything to do with the misfire?

I highly rate Evolve tuning and I am contemplating using them myself, I will be very interested to hear what they say and how they deal with this matter.

Certainly, as a backstop, there would be no harm in reducing the plug gaps a little and see if that helps if the coil pack change doesn't work?

[JK-M5]

I had the car down to them when i was home last week. 4th gear pulls on the dyno. car pulled solid a few times, seen the graphs, looked perfect.

Evolve said they where 36 faults in the system some relating to ABS which they cleared so i set off for home hoping it was solved but have recently shown since i have run the car again and the misfire is back.

they did suggest flashing the car back to stock which i did do and run it for a day or so and there was no evidence of the misfire soon as i flashed the car back to the stage 2 map misfire is back again.

Cars in now getting new set of coil packs and going to try and gap the plugs to 0.022 from the stock .0.34

fingers crossed. not sure why there are numerous codes showing under ABS code

[JK-M5]

However, many tuners will go to a slightly colder plug to avoid misfires after tuning and / or reduce the plug gap.

yes iv'e had cars with stage 3 tuning packages before which run the colder plugs with the gaps decreased. really got me thinking this time about possible fixes.

see how we get on today

[steeve13m]

Originally Posted by jonathon kelly

Anyone using lower gaps on tuned cars.?

had a problem with a misfire for a while now, only seems to be there from 4000 rpm in 3rd into 4th onwards.

annoying is an understatement, car has been fine but since fitting down pipes and a remap its there all the time.

changed the spark plugs out last month for the oem plugs from BMW still not sorted it.

changing the coil packs today and looking for info on the correct gap for the plugs if anyone has done so?

I have the JB4+BCM+Meth and running 0.020 gap on NGK SILZKBR8D8S Iridium Spark Plug 97506....I did it with a feeler guage for precision......I believe any tuned car should do this to avoid misfires

[Guy M5]

Originally Posted by jonathon kelly

they did suggest flashing the car back to stock which i did do and run it for a day or so and there was no evidence of the misfire soon as i flashed the car back to the stage 2 map misfire is back again.

Maybe need to try this again for more than just a few days if what you are trying now doesn't work?

Originally Posted by jonathon kelly

Cars in now getting new set of coil packs and going to try and gap the plugs to 0.022 from the stock .0.34

fingers crossed. not sure why there are numerous codes showing under ABS code

Fingers crossed the new coil packs and reduced plug gaps work for you, keep us posted on this one please Jonathon.

[JK-M5]

so the guy who does my work on the cars just got back to me he seems to think its fine its going out again tomorrow when there is less traffic to hopefully be solved

finger and toes crossed for this 1. because i'm out of ideas and its becoming an expensive find

[m5james]

The M5 isn't some magical machine that is exempt from common practices...go a step colder with tighter gaps already. This isn't new news on these forums, Google or in ANY car for that matter.

[boots]

I'm also using one step colder james. I think I went to .22

[steeve13m]

Originally Posted by boots

I'm also using one step colder james. I think I went to .22

you mean 0.022.....0.020 is recommended on JB4 setup

[allmotor_2000]

Go as small as you need for the boost you run. Larger gap has better burn as long as you don’t have blow out

[boots]

Yes 0.022. Thanks

[schnell1982]

From talking to DME, Mission Performance and HCP
A gap from .018 - .022 depending on your tuning seems to be the appropriate range.
Always best to consult with your tuner as they are the ones controlling the tune.
I agree with a step colder 100%

[hitenrallye]

Hi i the same problem after remap and decats, i have replaced spark plugs to lower temp and regaped them to 0.022 still the misfire at 6000 rpm in third. I have ordered 2 new Mafs and hopefully this work.

[apexlocator]

Originally Posted by hitenrallye

Hi i the same problem after remap and decats, i have replaced spark plugs to lower temp and regaped them to 0.022 still the misfire at 6000 rpm in third. I have ordered 2 new Mafs and hopefully this work.

Which cylinder? Maybe its your ignition coils?

[allmotor_2000]

Originally Posted by hitenrallye

Hi i the same problem after remap and decats, i have replaced spark plugs to lower temp and regaped them to 0.022 still the misfire at 6000 rpm in third. I have ordered 2 new Mafs and hopefully this work.

What's your AFR look like under WOT (to redline)?

[schnell1982]

Originally Posted by hitenrallye

Hi i the same problem after remap and decats, i have replaced spark plugs to lower temp and regaped them to 0.022 still the misfire at 6000 rpm in third. I have ordered 2 new Mafs and hopefully this work.

Why are you ordering new MAF's ?
What is your exact fault code description ?

[hitenrallye]

Hi no fault codes at all. Im getting new mafs as it hunts on idle and i swapped with a friends car and it stopped.
Fault is misfire under high load above 6000 rpm above 3rd gear. I still think its spark plug related to be honest

[Sales@RKautowerks]

Originally Posted by m5james

The M5 isn't some magical machine that is exempt from common practices...go a step colder with tighter gaps already. This isn't new news on these forums, Google or in ANY car for that matter.

Where did you get these part numbers and the respective heat index?

-R

[hitenrallye]

I put in NGK97506 plugs and gaped at 0.018-problem went away