I just bought a 15% pulley kit with plugs from Way Motor Works. It came with NGK BKR7EQUP plugs. Installed pulley and plugs. As soon as I started the car it started flashing the check engine light. I let it idle for 10 minutes, but as soon as I went to drive it the misfire got extremely bad. I put the stock plugs back in and the idle would smooth out. But they are a heat range #5.

Not sure if the engine needs to be reset or what to run the colder plugs. Any help would be great.

 

This is not my writeup but from a experienced Mini owner who has written a lot about performance mods. Hope this helps

"With my mods in my 02 R53 Ca 92 octane fuel even with all the other "witches brew" fuels and my average MINI engine mods. i.e. reduction SC pulley CAI,header,exhaust etc. As each was added I ran pug readings under load to determine the continuing or changing of the spark plug type and /or heat range.
I ran NGK ZFR6FIX-11 gapped at .46 tried .50 but it started to miss at 5k rpm so I went back to .46
Now I run AC Rapid Fires at the same gap with no plug miss-fires

The point is every Mini is different, consider to stay with the oem recommendation unless you are willing to take the time to do the testing and learn how to plug read correctly.

A couple of things.

When thinking about a spark plug for performance try to find a listing for a single electrode so you can dial the gap in for your specific engine. When you go the level of choosing a spark plug for performance use learn how to best gap them or the effort in the choice is partly wasted.

Never assume a heat range change from stock....... ever! Start with what came factory than do a proper spark plug reading to determine if a heat range change is warranted. The old charts indicating lean/rich good,etc. really do not apply when changing heat ranges for a performance application spark plug.
The basic rule gets so many into trouble. It should be written a basic rule of spark plug heat range estimate for advance performance enthusiast.

With advances in the last 10-15 years such as factory ignition controlled ECU's(controlling AFR's via timing perimeters) upper end aftermarket DIS or ignition systems, high end NOS and water, water/meth systems, etc. incorporating ignition retard and delay actuators to allow safely running a better average spark plug in order to allow the best possible combustion temperature to maintain a more consistent power level.

When you increase power to an engine monitoring at least your EGT's and watching AFR's to make sure you stay within predictable combustion temperature range so as not to allow increased heat in the wrong areas. If you are raising the temperatures or introducing induction augmentation changing AFR's by any engine modification then attention needs to be given to adjust to lower them back down. The biggest problem with increased compression is not the heat with regards to spark plugs but the ability of the plug to continue to have a proper kernal and not get bent.

All to often the home shade-tree mechanic assumes what works by the majorities usage and not carefully thought and testing. Finding the best spark plug for any specific end use is not easy nor is it cheap. There is no simple way to guess in the end if you are not diligent in your selective process of changing spark plugs you could end up with a melted spark plug electrode or worse?
Even the simplest thing as a spark plugs has highly technical consideration.
Recommendations:
Spark plugs NGK oem heat range unless you are going to do the needed work to determine another type and heat range.
Check you spark plug wires:
Spark plug wires are not all the same do the research and find the highest quality with the least ohms per foot.

When you change your plugs it is a good idea to use a little thread anti-seize on the threads, if single ground electrode check the gap and when installing properly torque them.
There is actually a torque value for spark plugs but few ever take the time to do it correctly.
Use dielectric grease on spark plug wire boots.


How power gap a spark plug:
Starting with standard heat range and single electrode plug factory recommended gap:

Doing this safely!

You make a full throttle pass...without taking your foot off the gas cut power. Stop and pull a plug.
Carefully view using a flashlight and magnifying glass all the way down the inside the spark plug. Simplified version assuming good AFR's and reasonable EGTs look for all signs of heating or irregular coloration, pitting, breaks etc. caused by a heat flash. If so this is the first clue to going a step colder plug. If you see clean un-blued area and some black you should stay with that heat range and proceed to gap adjustments.
After you have finally determined through trial and error of making a few passes with plugs found the proper heat range for your engine you can then increase the plug gap by .10 until you encounter a misfire. Then gap to -.015
This gives you your maximum gap at speed/load
Now for the extreme detailing of plug science you can index the plugs

 

I understand how the plug tuning works.. My issue seems to be an with adjusting for the new plugs. With the stock plugs and 15% I get a little detonation around 3,000 rpms, so I know I need to run one plug colder. I just can't figure out why my ECU will not adapt.

 

I doubt your "detonation" is due to running too-hot plugs. Sounds to me like you may just have a bad plug. I personally don't think running colder plugs is crtical with a 15% pulley. I'd put it back to stock and drive happily ever after.

- Mark

 

First, what was the code? General missfire or specific cylinder? This may help you with the whole bad plug possibility.

Or yes the ECU may need time to adapt, and / or there may even be a stuck adaptation that may need to be cleared.

 

The plugs in the kit are the same heat range as the jcw plugs.
Jcw cars run about a 12% reduction-the cooler plug is todeal with the exta heat.
some folks run a cooler plug depending on mods.
If you have misfires, check your work. You are running the highest octane fuel from your local gas station right? Stock software on the mini too right? (Not sharked, etc)
the plugs were tourqued right. Wires reconnected to the right terminals too right?!
The pulley mod has beenaround a lonnnnnnnng time...and has proven very safe. Your car was running 100% fine before the pulley right? Any issue can be magnified by the pulley...

 

Reset the ecu and the car is much better now. Full throttle its still not running perfect, but it seems to get better as I drive it. Check engine light is off as well. I am thinking tge Ecu may need to adjust now. I have only put 3 miles on it since the plugs went back on.

 

Check the gap of the plugs. 15% pulley can run stock plugs, but if you want to run the cooler plugs they should run fine as well. No ECU tune is needed at this level.

 

Make sure you have good fuel. It's pretty hard to get fuel with no ethanol in it, but whenever I'm running fuel with ethanol in it, full throttle on a hill climb is never good. I have to back off a bit. My car seems to run fine even at full throttle uphill when using pure gasoline. Some folks here are using 94 or higher octane with no ethanol in it. That seems to be the way to go, but you're paying more for the fuel.

 

Got everything running good now. It wouldn't adapt for the plugs so I had to reset everything. Vibration damper is making noise now though.

 

Not sure what you mean. There is nothing to adapt to with plugs.... Most likely you had a bad connection or they weren't gapped correctly.

 

Previous owner put hotter plug in the engine by mistake. The ecu wasn't adjusting the fuel at all no matter what I did. Only resetting the ecu fixed it.

 

There is nothing to adapt, as I said. The plugs are you talking about are cooler plugs and that has nothing to do with the actual spark but rather the plugs ability to function in a certain heat range. If you had to reset the ECU (which has never been proven to actually work) then I think you have something else going on like maybe a bad plug wire.

 

The ecu was reset from a BMW tech not the instrument cluster way. It was misfiring right before he reset the Ecu. As soon as he reset the ecu the car ran perfect. Not sure what was going on but resetting the ecu fixed it totally without touching a spark plug or wire.

The ecu does control fuel last time I checked.

 

This is what I was talking about when I said "stuck adaptation" sometimes if the car runs with an adaptation for so long it just won't re-adjust and you have to have it cleared manually.

And yes the ECU does make adaptations to the fuel maps to get the proper ratio for the specific amount of spark supplied.

 

Did the prior owner have a custom tune?
If they had any of the maps set on the fringe that could have caused your issues.
Don't hesitate to call Way with any issues. He is very helpful.
Glad you are good to go now.

 

Never heard of a stuck adaptation before. This would be a first.

As for the plugs, they are minimal as far as ECU adjusting is concerned. The pulley would have caused a bigger issue if it was a stuck ECU. I still think there is another issue there like a bad wire or as someone mentioned a bad pack. Could also be a bad gap on one of the plugs.

Either way, I am glad you got it working.

 

I've only had it happen to me once, trip to Denver, once I got so close (altitude) the car wouldn't idle at all, got the adaptations cleared (before I had the F/A) and ran perfectly.
Probably not a normal thing but for my car it wouldn't suprise me if it never happened to anyone else.

 

Hello

Sorry to hear about you luck with our plugs, for a pulley swap a heat change is not something we should be doing. We only change heat ranges for compression, upped boost, or nitrous. In this case we should stick with the stock heat range.

If you have further questions please feel free to call our tech support line at 1-877-473-6767 ext. 2

 

This is a fascinating response. It seems like most of the "kits," (at least WMW and Alta) include colder plugs w/ a 15% pulley.

 

Hello

I have to apologize as I thought that we were talking about a underdrive pulley. The 15% for the mini increases boost 3-4 lbs from what I see and this is not a real concern for changing heat rating either way.

Thanks and have a nice day

 

The factory JCW kit came with colder plugs as well and only reduces the pulley size by 11%. Could it have to do with the flow of the JCW head?

 

Hello

No when we look at modifying heat ranges we look at a few key things

1. compression ratio - if the head modifies this then maybe
2. ammount of boost via turbo or charger
3. nitrous

If these are not modified there is no reason for the heat change, header, CAI etc... do not require a heat change

 

cboyd1, you mentioned the previous owner put in hotter plugs by mistake. From what I have read previously, even though MINIs should come with BKR6s from the factory, some came with BKR5s. It had to do with where they were delivered to in the U.S. Both my old '02 MCS and current '06 MCS had the BKR5s from the factory.

I do find it interesting you had to get an ECU reset for the plug change. I never had that issue with either of mine when I upgraded to BKR7s, for which they were combined with the 15% pulley upgrade for me as well.

 

The change in heat range is done to match the factory plugs in the factory modded JCW car...same motor, same compression, etc. Only change was about 12% reduction and a mild porting in the head. So a 15% reduction is a bigger reduction..more boost, more heat than the factory hotrodded car...so using the same heat range plugs as the factory hottrodded car seems prudent.