I have a 2006 mini S. Has 380 JCW injectors, 15% SC pully, Craven CAI, Miltek cat back exhaust. Having problem at low rpm. Under 3000 wants to crap out and sputter. Above 3000 it's a little rocket. SC boost to 15 at 7000 rpm. Why is it doing this? Runs at 900 rpm idle smooth.

 

Is your CEL on or any codes present? When was the last time you replaced routine maintenance items, i.e. spark plugs, coil, fuel filter, etc?

 

Just had routine maintenance done with oil change still has stock coil, new serp. belt and idler pully and Harmonic balencer. Car pulls hard from 3000 to 7000 rpm. No codes. What is CEL?

 

Yellow check engine light, and or stored codes

 

How long have you had the new injectors in? Used new o-rings?

 

Check engine light. I'd check for fault codes in the system. Not that this would be your issue, but I have seen this same issue with some BMW's before and it actually ended up being related to the ignition coil.

 

The injectors are about a year old. The only check engine that came on was when the Harmonic balancer went bad,but codes were cleared for that. Do you think i need to have a tune done for the lag and hesitation at low rpm? Was reading about the plug in tuner SHARK ECU upgrade or should i try changing to a MSD coil first?

 

DON'T SHARK IT...
It's just a timing advance...lots if folks burnt valves from it...not a good option IMO.

 

Did you make any changes before it suddenly started to run bad?
I ran JCW 380's for a bit untuned, no issues....
Plugs recent? Ever done a compression check? No pending codes or misfire codes right?
Some like the msd coil...I used one, no issues, some hate them. Consensus is a stock is fine...just has to be functioning right....
Check the plugs on it for corrosion? Wires OK?
Total miles?

 

Has 105,000 miles. re-capped the plugs from .45 to .35. About a week ago. Seem to run a little better.Runs on NGK BKR8EIX Iridium plugs. The guy I got the car from said he always ran the BKR8EIX. That what MiniCorsa put in. He did say when I bought car that it had a hesitation at take off.

 

I have owned car since January, always had a lag at take off from stop.. Other then that the car is great. Very fast. Need to take to Mini of Monrovia to have alarm programed. They said they could let me know what tune car has at that time.

 

ZippyNH have you had your car tuned yet with the 380 injectors?

 

Yup...ran untuned for maybe 3 months...dynoed 180 with stock exhaust, then had RMW tune it...got 200 with a very safe tune, still 100% stock exhaust.
The car will run a but rich with the 380's WOT, but the car will adjust with info from the o2 sensors when doing cruise acceleration...You will see this info in the fuel "trims" info if you have the software, and also an inaccurate mpg reading on the computer....till the tuner updates the ECU with scaling for the injectors...folks can sometimes run as large as 420's or even 440's on occasion if they have a header and headwork before they have real drivability issues due to being too rich. Yes, you will be "**** azz rich" with 380's and no tune as wmw put it, but most seem to run OK...longer term, might not be great for the cats, or even oil, but folks have done it for a few years, OK.
My car ran fine though...still stronger than stock with the 17% pulley,CAI, and 380 JCW injectors...

Any chance you swapped the. Map and t/map sensors by accident when doing work on the car? They look the same, but are different....result can be similar to what you see...

 

A bit if hesitation at takoff as the car gets airflow over the intercooler....they get heat+soaked.. normal...higher octane fuel, we have 93/94 on the east coast, reduces the timing pull from the excessive intake temps, then you will feel a slight flat spot around 3000 rpm as the BPV closes and the car switches to boosted operation....
What is not normal is a stuttering feeling....
The sparkplug wires usually have a date of manufacture on them with the cylinder #....they are so short they rarely fail....
I was also under the impression that the 4 prong plug could not be gapped,just like the iriddium ones....

 

Sorry for the mistake. I do have the NGK iridium plugs BKR8EIX,just took the plugs out to check color. no oil or wet. Dry and light brown color. Did try running the NGK BKR7EQUP ran like crap. Was told that running the JCW 380cc injectors would be fine, since having 15% SC pully with CAI and Miltek Exhaust. i do run 91 from Chevron weekly. Did run 110 octane from 76 for a week. Car did not lag or hesitate, but cant afford to put that in every week. Never touched MAP or Tmap sensors. Previous owner did say it had a JCW 210 tune. Im not sure if that true or not. Car does have full JCW suspension and brakes.Wont know what tune it really has until i take to dealer for alarm program. They will check then.

 

Do you think that the heat range on plug is to cold. I live in los Angeles and it gets hot here. I have not tried going to a NGK BKR7EIX. What are the symptoms of a plug to cold in range?

 

A too cold plug will result in hard starting and poor mpg...and increased plug foweling...they are too cool to burn off any contamination.
As long as you have the "JCW" heat range plugs, which are the "S" plugs, but one step colder....
If you have the iriddium plugs, and re gapped them, I wonder if you cracked them...they are very brittle, and generally NOT considered re-gappable....very gently, a few folks have done it...

One or two people have run plugs that are TWO steps colder...that is s -2 or JCW -1 for SPECFIC reasons or issues...

 

So I should order a new set and stay with pre-set gap of .30. With 91 octane from chevron.

 

Spoke with Jan at RMW. Setting up a time and date for him to do a tune on my car at his place in Irvine.

 

John, you really should have read the old plugs to see if switching to a two step colder plug was necessary. With your current mods, one step colder is a good place to start, then read the plugs at next oil change to see if you should.

Gapping a plug to anything above .032 is not recommended UNLESS you have Hi-Po Coil pack such as MSD ( Go with the MSD wires ). A stock pack doesn't have enough power to make an efficient arc across the electrode gapped above .040.

If you have bumped it up to over .040, while still running stock coil pack, bring it back to .032 and see what happens.....

 

And like Zippy said, Sharks are best left in the Ocean. If you have the JCW tune ( as Prior owner stated ) so the injectors are pulsing a proper rate just stick with that so the engine's fuel/air management systems have no conflicts.....

 

Put new set of plugs and wires yesterday. Stayed with the BKR8EIX. The BKR8EIX plugs I pulled out had a nice light brown color. Even color across all 4 plugs. So thats a good sign. Set gap at 32. Took car for test drive and seem to not have the lag I was having. Wish I new how to post pictures of plugs.

 

To determine the proper heat range when reading plug, it is determined by how deep the threads of the plugs go dark....

When you install the Hi-Po Coil Pack, you can open those gaps up. I performed about dozen tests of various gaps beginning at .045 and went wider from there.

In the end I believe I ended up at .052-.055, ( results vary depending on mods ) which creates longer arc / more spark = more efficient fuel burn = more torque/power.

GL.

 

Or if you are last like me, the gap just widens with wear!!
Jk, but do know of you start at the wide side of the "acceptable range" you might need to adjust them slightly more often....
JCW cars had a recommendation to change the plugs at each inspection, so about 30,000 mes if I recall right, while "S" got them at "majors inspections, aka #2, so about every 60k if I remember right....if you have a pulley, imo go with the JCW suggestion for service.
One more tip...be sure to check the tq of you plugs in a couple days...many folks have had spark plugs shot out, and needed helicoils, etc cause it can be hard to get a GOOD tq in an aluminum head and not over tq it at the same time.

 

Jan does good work...try to get the car running 100% before a tune.
Have a chat with him...about what you want from your tune...
I asked for a good reliable tune for a dailr driver....
For those looking for bragging rights he can push limits a bit more....but also slightly more risk .
When he does the tune, he can adjust you gas pedal a bit, kinda like a poor man's "Sprint booster "...will not be adjustable, so it is set kinda mild to make bumper to bumper traffic doable...
Another thing he can adjust is you DSC or ASC+T....Makes it much nicer...it will not kick in on hard launches and when you do slide a bit, it will not cut you throttle by the full 50%....makes the car much more drivable....imo the way it should have been set from the factory.