R56 JCW - stage 1 remap odd issue?

R56 JCW - stage 1 remap odd issue?

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Discussion

gex23

Original Poster:

22 posts

147 months

Tuesday 3rd December 2019
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Hi guys,

I have an R56 JCW with 66k on the clock and recently had it stage 1 remapped at a well known mini tuner

It really has transformed the car and produced reasonably healthy figures of 239 bhp / 330nm torque.

- All is well and good bar when I change gear between 4 and 5k under load, it seems to judder ever so slightly and the revs drop below 4k before power comes back.

- Doesn't happen under 4k or over 5k rpm

- Doesn't seem to happen when I let off the throttle in the same gear between 4 or 5k rpm either.

It's going back in for coilovers soon and they have kindly offered to take it out and see if they can replicate the issue when it does

But i'd like to know your initial thoughts on this

N.B. - Stock car bar high flow air filter and NGK iridium spark plus which where fitted just prior to the remap / Dyno

itsnotarace

4,685 posts

216 months

Wednesday 4th December 2019
quotequote all
Likely needs a decoke

gex23

Original Poster:

22 posts

147 months

Thursday 19th December 2019
quotequote all
itsnotarace said:
Likely needs a decoke
It's the N18 not N14 engine so i'd be surprised? Also idles fine and made good power when dynoed?

Still suffering this issue - wondering how it can be boost related if it doesn't occur when I remain in gear and rather does it during a gear change between 4 and 5k?

TimmyMallett

2,975 posts

119 months

Thursday 19th December 2019
quotequote all
Doesn't the ECU do something with the throttle when you clutch in? I've noticed that when pulling away in 1st with no throttle (just coming off the clutch) the revs rise by 3/400 RPM to give you more torque to stop stalling. If that's the case is it possibly linked to that?

gex23

Original Poster:

22 posts

147 months

Thursday 19th December 2019
quotequote all
TimmyMallett said:
Doesn't the ECU do something with the throttle when you clutch in? I've noticed that when pulling away in 1st with no throttle (just coming off the clutch) the revs rise by 3/400 RPM to give you more torque to stop stalling. If that's the case is it possibly linked to that?
Tim cheers for the reply!

Rather than the revs rising they drop below 4k before power resumes?

If it's ECU related i'm surprised more people / everyone that's got a remapped car doesn't suffer the same issue and yet it seems it's isolated to me / my car?

Never happened running the stock map either...

GaryF

974 posts

260 months

Thursday 19th December 2019
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This must be infuriating...

The tuner not able to diagnose this for you? You could take it to another, but they will likely have to charge you for the pleasure frown

gex23

Original Poster:

22 posts

147 months

Thursday 19th December 2019
quotequote all
Very infuriating. It's running a very popular map using manic motorsports software where issues seem few and far between. I just don't know where to start!

GaryF

974 posts

260 months

Thursday 19th December 2019
quotequote all
I'm running a Manic map too myself (stage 2). It's brilliantly powerful. Sorry, this does not help you with a fix though...

itsnotarace

4,685 posts

216 months

Friday 20th December 2019
quotequote all
gex23 said:
It's the N18 not N14 engine so i'd be surprised? Also idles fine and made good power when dynoed?
N18 is still direct injection and whilst the changes have helped the issue they have not eliminated it, just slowed it down. All DI engines suffer the same fate

From my own experience the same symptoms happened to mine and a decoke resolved it

YMMV smile

TimmyMallett

2,975 posts

119 months

Friday 20th December 2019
quotequote all
I'd refer it back to the map supplier for support. It may help diagnosis if you get it on a rolling road to see where it happens? I suspect though that if it would be an issue with the map it would affect all cars using it and be spotted and rectified by the supplier pretty quickly. Sounds like fuel, so injector test? Or a failing fuel pump, or even an old battery may cause this possibly?

I'm definitely no expert though, just what I've seen on mini2 and others.

gex23

Original Poster:

22 posts

147 months

Tuesday 28th September 2021
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I thought i'd bump this in case anyone had any further thoughts.

The car is now on 73k, and the issue is still apparent - between 3900 and 4500k revs - basically change any gear then and there is an immediate hesitation while it drops below that rev range then the power comes in, all in about half a second or so. Happens in all / most gears. Doesn't occur either below the 3900 or above 4500 and pulls strongly to the redline.

It hasn't gotten any worse (or better) in that time.

I've had general servicing done (fluids / spark plugs) along with all coil packs last year but no improvement.

My thoughts were either new injectors, or a walnut blasting de-coke as advised above (though this is an N18, will it need benefit from this?)

Anyone else able to offer insight? I'd love to solve this as I want to be able to enjoy the car properly again!

Thankyou for reading / offering any input.

rigga

8,754 posts

208 months

Tuesday 28th September 2021
quotequote all
Get it wallnut blasted, yes the N18 should suffer less, but it will accumulate due to the nature of direct injection, for £200 or so, its what I would be doing.

GaryF

974 posts

260 months

Wednesday 29th September 2021
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I had my N14 walnut blasted when it was in for the tuning work. Apparantly it wasn't too bad, but good to get it done to see if that helps you. I'd be going mad by now almost two years on. Good luck, and let us know if it helps.

TimmyMallett

2,975 posts

119 months

Thursday 30th September 2021
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The obvious step is to get the remap company to put the OEM map back, test and see if persists.

You can get the coking checked visually to see if it's actually likely to be the root cause. You would have noticed it before the remap though. Sounds like it was there before and the remap has exacerbated it, have you got it on a RR to monitor stuff like AFR, fuel rail pressure and turbo pressure when it does it?

If it pulls to the redline fine then it probably isn't the HPFP which is a bit of an issue on those, maybe a faulty MAF? O2 sensor etc etc Any error codes?

That would be my next step.

Edited by TimmyMallett on Thursday 30th September 12:08


Edited by TimmyMallett on Thursday 30th September 12:08