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Discussion Starter #1
I'm not in the UK just now so cant offer a lot of information on the problem.

Its happening on boost, and seemingly exiting corners.

Here is a vid from Oulton warm up which shows the problem a wee bit.


Fee said:
Please ignore all the shite at the start... the problem comes up at 6.34, a little at 7.18, 7,28, 7.59

....it isn't consistent....it isnt every time I hit 5.5k revs....it's randomly
and in the vid there it looks as if it's mostly coming out of corners, but it was random too....coming out of corners, on straights, anywhere really!
What are your initial thoughts on the problem?!

Fuel system - has enough capacity, has surge tank and has NEVER suffered from surge before (with grippier tyres and more power)
I dont think its a traditional misfire - to clean like a cut in power.
IGN cut of some kind?
 

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It sounds like quite a hard missfire... It also sounded like it became more frequent as the car got hotter, Im thinking a good look at the coils and associated electronics would be in order... All the usual stuff like checking the earth wires etc.

Its hard to tell from the video, but the sound was a bit like a blow off valve being forced open or a split pipe suddenly throwing some air out, I wonder if a quick check of all the air pipes would be an idea while your under there...

Did it feel like it was dropping onto 5 cylinders ? or was it more like the whole engine missing a beat on all 6 ?
 

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Discussion Starter #4
its not turbo shuffle
Its not a bov - no bov's
its not dropping to 5 (that I know of) - that wouldnt cause a full on 'cut', just a drop in perormance.

Wiring issue was my first thought after seeing the vid..... happening when the car is moving round

before seeing the vid i just thought it was a plug/coil misfire, but it really doesnt seem like one

(Its not me driving - so trying to get info from Fee to try and work out what the problem is LOL )
 

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If its all 6 dropping, then this goes some way to ruling out plugs and coils, might be worth checking out the engine earth wire and the earth to the coilpacks... then moving back down the loom... Its and R32 ? Does it have the coil resistor pack ?

It does seem to be reacting the same way a broken wire or loose connection would.

Yea, I think check the earths, then check the wiring from ecu to coils... I wonder if a loose connection on the crank angle sensor would cause this too ? In fact, It doesnt take long to break/check and reconnect most of the under bonnet wiring connections.
 

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the noise you can hear is air coming back through the airfilters missfiring doesnt cause this, as for loosing all 6 cylinders! i cant see that either as you can hear the engine driving through it, it sounds exactly like the turbo shuffle i was getting with my 2860's before i mapped it out are you still running mafs as if so that would cause the drop in performance, if not it must be something else as when i swopped to the link i still got shuffle to start with but it didnt effect performance, the reason it may seem like its due to corners is that the revs are lower coming out of the corner than on the straights i was getting the shuffle at approx 3-4000rpm
 

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I suspect between the OP using second hand info and the video having noises in that might not be related this is going to be very tricky to clear up... Your going to have to get your hands on the car and consider all of the above while driving, see if you think any of it fits.
 

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Discussion Starter #8
its on MAP sensors, it is NOT shuffle.

I know what shuffle is like on these and this car in particular and this isnt shuffle.

The sound of the air coming back through the filters is exactly why I dont think its simple coil/plug misfire - but some sort of ign or fuel cut that basically causes the car to stop accelerating and simulate lifting off the throttle which results in the same noise.

The car is not road legal but will be on a dyno soon enough to try and replicate - may be hard with no corners to simulate movement LOL
 
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