Okay first off hello, I'm a newbie to the scene. I have learned a lot from all you folks in the past couple weeks since I bought my R3. Being a motorhead at heart I had to start the obligatory upgrades, so I did a DDM CAI, Magnacore wires, MSD coil, and a set of Brisk plugs 15YS heat range. The car ran fine and idles smooth with the factory gear on it but since I changed those items it seems to have stumble (for lack of a better term) at idle, otherwise it screams. I have read lots of idle posts but none seem to have the same precursor to the problem, the plugs are gaped at .026 per Alta. I was thinking about going back to stock plugs since the rest of the motor is stock but I don't know yet, any help or comments are appreciated.

 

If you weren't having any problems with the stock coil pack & wires, I'd put them back in and see if the stumble goes away. If it doesn't I'd try going back to the stock plugs as well.

The factory MINI ignition components are actually pretty good, and there's no reason to replace them unless they fail (or you've reached the recommended change interval for the plugs/wires). There are a lot of professionally-built MINIs running around with 250 WHP (or more), still on the stock ignition parts.

 

I would but it looks like mice had nibbled on the wires, I think I will try plugs first. Also number 3 post on the coil pack was rusty looking.

 

Yeah, corrosion on the coil's #3 plug receptacle is pretty common - not sure what causes it, but it cleans up easily enough.

 

Don't forget the mini has stored parameters called "adaptations" and until it updates them, it still is using the old info which may not be exactly correct. Search "clear adaptations" and I think you can clear them right away to rule that out.

 

Does the MINI have any ECU adaptations other than short- and long-term fuel trim? My understanding was that if you change anything like parts or fuel that affect the optimal fuel mapping, the short-term fuel trim will adapt to new conditions in a matter of seconds and even the long-term fuel trim would adapt in a matter of minutes.

 

I did the ECU clear using the odometer last night with no positive results, unfortunately I don't know a ton about the car since I'm not the original owner and it has 45K on it. there were a few pieces of paperwork where it had a thermostat housing replaced along with both O2 sensors under warranty but that's all. A friend of mine is a dealer local and he had for a while so he let me have the car at his cost. I caught the fever after my wife bought a 2011 clubman "Hampton edition". This cars runs super except for the idle now. Keep the ideas coming I really appreciate it, you guys are super knowledgeable and helpful.

 

The "ECU clear" using the odometer button doesn't do anything - it's just a reset of the instrument cluster itself. If you use a scanner to check the fuel trims before and after a cluster reset you'll find them unchanged by the process. Some people will claim a difference afterward, but I think it's likely just a placebo effect.

The thermostat housing is a pretty common warranty replacement - we had to do it for both of our 2006 MINIs.

 

I think that gap is smaller than what I use. I think I am at 30 (at least). You might want to give it a try. A high end coil should be able to gap .30 no problems.

 

actually 400hp


gap your plugs to .030 to .032 and you should be fine
you should have bought one step colder plug

 

Yeah, I knew you had a monster out there running around on the stock ignition but I couldn't remember exactly how much power you were making - that's why I weaseled out with the "or more" part of my post!

 

no issues Scott, I'm always amazed at what is sold to people when most of the stock parts are pretty good

 

I had the same exact problem and it was the brisk plugs. If you are running the stock head you should run the ngks one step colder, this will fix your problem and I did end up putting my stock coil back on.

 

Update... I put a code reader on to find no codes so I switched back to the (new) stock plugs and problem fixed . I will keep the MSD ign and wires only because the stock stuff was damaged and ready for replacement, it runs great. Way better from the haggard gear that came on it. pulls ways smoother through all the R's and idles like a kitten purrs. Thanks for all the input.

 

Just be sure to check the tourqe on the plugs....
they have been known to loosen and get blown out, tearing out threads...
A tourque wrench is a good idea, but double check them after a few heat cycles....many have learn the hard way with the mini's head.