So yesterday I installed WMW's 15% pulley along with a smaller belt and one step cooler ngk's. (pulley package) I don't have the JCW r53 so heat range 7.

I am now noticing a stumble upon WOT and downshifting. I do believe its early detonation but am no mechanic so I am not certain.

I live in North Dakota right now and its 10 degrees outside, could this play a part in the pre-det?

Also I ordered a set of two step colder plugs and was am going to try to troubleshoot the problem Tuesday.

Any help would be greatly appreciated for its not so fun having pre det.


Thanks

 

What are you you running for fuel?

 

I am skeptical to think 2 colder, especially during a nd winter will help...many run stock till warm temps, and then see a stumble.
Any codes? Pending or set?

 

Stock plugs here with 15% and never a stumble regardless of temps.

 

Putting plugs in it is just throwing parts at the problem. If you think it is plugs you should put the stock ones back in.

But I'd guess your problem is more like a plug wire or even coil pack. Check number 3 terminal you'll prob find it corroded.

 

Going on a complete different tangent than everyone here.

Are you still running OEM BPV?

If it feels how i think it sounds, a sticky BPV could be the culprit, and is a common occurance in R53s. DT makes a great replacement.

 

I am running 92 octane from aafes every time I fill up and use injector cleaner etc. Running stock BPV as well. Stock plugs it does the same thing. I resulted to colder plugs because of this. I have cleaned all terminals on coil pack. I also have a full alta cai if this matters?

OH and no cels.

 

No CEL's are a good sign....Fuel should be fine, especially with the temps...
Maybe the feeling/sound you are getting is just a temp thing as the computer adapts to the pulley.
I'd drive it gently for a tank or two of gas...then wail on it again...and watch for CEL's.
Remember...most injector cleaner will reduce octane a bit...
The computer seems to be pretty good at detecting Detonation/misfire events....so no CEL's..is a good thing!
I did notice that my car did not seem as "smooth" with a pulley...a bit more "course" at higher rpms, "WOT".
When I put the JCW 380 injectors it...it seemed to smooth out...and the tune smoothing stuff out to better than OEM....

 

Well I'll take a shoot in the dark. Could it be that I installed the pulley crooked? Sounds crazy but the way the 4 binders grip down on the snouts shaft it seems like it would be quite easy to mess that up. I am 90% sure its pre-detonation at wot but has anyone else noticed that about the WMW pulley?

 

A Crooked pulley would cause noise with the belt (along with wear)....it would not affect the production of boost....
One thing to think about....
A when a pulley is installed, the computer can use the o2 sensor at light throttle use to maintain a proper mixture, but at WOT, the car must use maps of fuel volume/intake temp to determine the proper mixture....
This means that at WOT the motor will run a bit leaner...the 15% has been used for years with little issue...but if you have a partially plugged injector or something you could get one cylinder running lean, or maybe have a weak fuel pump, etc, which could cause an overall lean condition...either of the above would be expected to set a code/CEL.
I'm guessing that the extreme cold (more dense air= more fuel needed), and the extra boost might be causing you to run leaner than average for a pulley car when you stomp on it...
My suggestion....clean off the black soot on the tail-pipe, and keep an eye on it...check the color in a few days...black (rich) is normal on a mini...if you see gray or white soot, then you are far too lean...
Most MINI's do fine detonation/knock wise with 15%, 17% is usually OK, with some folks finding 19% to be just a bit to far without mods...so with a 15, if everything else is OK, it should be fine.
IF you have access to it, try to do a compression check...make sure the compression is good...
Maybe you need to try a different gas station? Maybe it will help...I know even though fuel tends to be pretty standardized (it is typically transported in shared pipelines, so usually it is just the additives that are different), some MINI's just don't do well with fuel from some stations...maybe the wholesaler is passing off slightly out of spec fuel...

 

i didnt hear anything about a sound, pre-detonation would make a distinct sound and you wouldnt necessarily feel anything. so it isnt that. your pulley is not installed crooked, it would be very apparent, again, more noises that are absent from this thread.

your fuel is adequate

dont use any adatatives (fuel injector cleaner can do some strange stuff)

zippy makes a good point in checking the mixture with the soot on the tailpipe, do that

way made an excellent point with the plugs and wires, and 2 stages colder is unnecesary, go with what works (BKR9eix-11 I believe)

I have a WMW 17%, and I had pinging(det), your symptoms are not reflective of that problem. but FYI there is an entire thread on a/f mixture and using larger injectors and tuning to fix that problem.

like Way said, dont throw parts at the problem, make a proper diagnosis and report back if those items dont pan out.

 

What do your plugs look like? You can learn a lot by "reading" those, that is usually the first place I go working on bike motors.

 

When I'm running 91 octane with up to 10% ethanol fuel, at WOT going uphill, I get some detonation. A switch to 91 octane pure gasoline or 94 octane pure gasoline got rid of it.

My car has a 15% pulley, MINI-Madness CAI, and 1 temp range cooler plugs.

I am suspecting the ethanol. Unfortunately, it's getting more and more difficult to find fuel with no ethanol in it. Special thanks to the US corn farm lobby and our politicians.

 

^ I second that statement. Well today during WOT there was no det. I ran my tank to almost empty and filled up with 92 octane with the oh so great ethanol additive. Runs fine with no stutter. I bought new plug wires and will replace those just in case but my best guess is that it was the gas I was feeding it.

Thanks all for helping me diagnose/solve the problem!

 

Why would Ethanol make your car ping? E85 is a godsend for FI applications, and that's 85% ethanol. Something else is amiss, as higher levels of ethanol resists detonation more (and releases less BTUs and yadda yadda).

Aka the Ethanol shouldn't make your engine ping.

 

Good to hear the car is running better!!
Sounds like you car did not like that blend of fuel.

Since a Mini with a pulley has the injectors running 90+% duty cycle....it does not take munch to cause issues...many people suspect that since BMW/mini does not tune cars to run on e-10, the motors might go a bit lean dur to both the duty cycle limits, and computer programming.
The adaptive nature of the computer and the fuel trims when you were in transition from WOT to light/off throttle might have played a role also... The computer was in effect learning how much extra fuel to pump to keep the mixture right when not using the maps for WOT...
What I can tell you is before tuning (even before my pulley) many Mini's are finicky about some fuel quality) Mini's do only ok on e10, but after a custom tune, my car runs better than factory on e-10...
Solved the ethonol problem for me!
Since e-10 is now getting rolled out the Europe, it will be interesting to see if the tuning/programming changes on future and even current european cars.

 

The computer is only going to update those parts of the map really. Some ECU's (like the Adaptronic I work with) have setting that let it change other parts of the map from just the one part it happens to be looking at, but you only set you ECU to do that if you are roughing in brand new map.