On driving the car hard on boost with the oscilliscope connected on live date the ecu randomly shuts down 2 cylinders.
Around 5k this flatlines on boost @1.45bar.
This has all been recorded.
The feed and the earth are still live.

So theres an open circuit instead of the pulse earth.
Wait 5 minutes.Go again and it shuts down another cylinder on hard boost.
This is controlled by the ecu not oil pressure.

So in this case im going elsewhere for better results rather than excuses.

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its been tuned be kream development and is running 580bhp "supposingly" and i honestly thought there was no way in hell his coupe would even keep up with it! total shock and iv got the video for proof

flea.........not too bad mate!

Is that your mate with the Blue 420bhp?

I'm not sure what you mean by a 'live earth' but it seems to me that you have a problem with the electronics - or the 'hardware' - of the ECU. This is quite different from a problem with the mapping, which is 'software'.

True, but they are using 2 ecu's to control each bank, so only 240bhp per 4 cylinders

Is it the original ECU to the car John ? If it is, maybe give another coupe ECU a chance in the car. I am sure it's not a big or expensive job to try that out.
Or am i blowing from my bottom ?

true but i know of a couple of 700bhp escorts running p8

no,sounds like a MUCH cheaper option,ecu could have a fault,so all the mapping in the world wont help.

i was going to suggest but thought

a) it must have been tried, or
b) it's far too simple a solution, or
c) i'm too thick to grasp most of what the hell you're all on about

i settled on c)

laymans questions...
does this ecu have limits?
will they be reached by highly tuned cars?
could this be the case with johns(reaching some sort of limit)?..
are we talking from a perspective of knowing all the maps and codes therefore being able to say for certain john you have got an ecu issue not a softwear one?
or could it be that if all is not understood fully his car could be throwing up some fault/limit code as yet unable to be interpreted (software)?
could it be due to pushing the limits of this systems unknown(un read/uninterpreted) parameters or causing an issue in an unknown one?

I would say that if there are any limits, as Flea has surpassed the power output of this vehicle with other cars, he would know if that was an issue......

One thing that did occur to me, is what the OEM software does when it detects low oil pressure? I would expect it to do something to protect the engine from destroying itself.......

It does absolutely nothing; and for good reasons.

First, it doesn't know; there's no input from the oil pressure sensor or switch to the ECU.

Second, if it were to see - for example - a short term low pressure caused by, say, oil moving in the sump during hard cornering, it would be in the invidious position of damned if it did and damned if it didn't. If it stopped the engine, there's a significant chance of dumping the car in the nearest hedge...

An input which inhibited *starting* the engine until sufficient oil pressure had been reached would be beneficial - I think Jaguar did this some years ago - but it should never stop the engine if it's running.

You have taken my wording the wrong way.
With 2 lives it obviously wouldnt start not to mention the car would catch fire.

You have a permanent earth,which i have bypassed and made direct to the chassis then battery to rule out brittle wiring to the coil packs.At first the voltage dropped to as low as 7 volts on full boost.
So the earth was altered to allow a constant 14.5 volts on hard boost.

You then have an ignition 12v which reads on a voltage check on the oscilloscope 14.3 volts when the relative voltage is 14.5-6.
So nothing to worry about
The third wire is a pulse earth from the ecu.Almost impossible to meter unless using a laptop and oscilloscope.
This is where my issue lies,and its clear as day that at random the pulse earth is being lost.
Theres less than .001 Ohms resistance in the wiring.

Theres nothing wrong with the electrics,the issue is what i have mentioned above.
This is the 3rd stock ecu i have tried,3rd lot of coils,2 types of plugs,5 times i have done a boost leak test,4 comp tests and 2 leak tests,all the plenum donuts are new the afm voltage reads correctly as does all the other live data.
I have even checked the live data of mine to another coupe running the same power and similar setup and there near identical on the oscilloscope.
Theres no issues what so ever with the car.

As for oil pressure its fine and holds over 2 bar all day long.The issues with the oil pressure are with increasing oil temps on the track which drops the pressure to around .5bar hence why the shell clearances are being checked and a new uprated cooler is being fitted.

I spent 7 years working for Peugeot and 3 years as a Mastertech working solely on electrics.
I worked from a dealer but was also active at the factory in Coventry,.
I used to work on all sorts of faults which defied belief.
Anything from pumps injecting 1600 bar on idle to rear wipers activating during driving.
They were some seriously complicated multiplexed electrics that used 2 wires with a digital signal.
But then changed during the same model.So they were different by a build code.
Coupe electrics are very straightforward,and on the whole very reliable.
The design offers durability and reliability.
As above my issues may be exclusive to my car but all cars are different hence the live map.
Similarities are few and far between even on identical cars.
Each responds differently to mapping.
My motivation here is not to undermine or criticize but to sort an issue that no one seems to be able to get to the bottom of.
I want to reach the potential the car has to offer without the gremlins that it brings.
For me losing the Maf is a bonus as its a huge restriction to modifying both in its capabilities and its inaccuracies between intake and manifold.

JBT - nobody is going to argue that you're clearly having ignition-related problems. To have a couple of cylinders shut down on boost is a severe symptom, especially when its a different couple of cylinders the next time.

However, I'm struggling to believe its the mapping. As you know, I've been running a Flea map for ages now - I was one of the first. Leighton definitely struggled at first with getting my car just right, but he persevered and eventually, it got to 99% correct (the transition from dead throttle to a tiny bit of throttle is still a bit sudden for my liking, but Leighton can't make it any softer and I can live with it).

My point however, is that Leighton hasn't touched it for a couple of years now - I haven't changed anything, so there's no need for it to be mapped - I reckon the engine has done 50,000 miles since he last worked on the ECU and its well over 100,000 since he first started playing with it.

I think you may have coil issues - when I was trying to run a big plug gap, I was getting random misfires on one or two cylinders - it was never the same cylinder twice running - just completely random. We proved the issue by running a small plug gap for a while (0.6mm) - it dropped the power quite noticeably (smaller spark, less burn) but the misfire went away completely. The other thing that contributed was the wiring loom. The copper had broken down and was causing resistance issues - I spliced in a new loom and the misfire never came back, even when I opened the plug gap back up to 0.75mm

Another small mod that I'm convinced made a difference was the doubling of the earth leads from the block to the chassis, and the chassis to the battery. I left the standard cables in place and ran a fatter cable from the gearbox to the chassis leg and another one from the chassis leg to the battery. It might have been a placebo effect, but I'm convinced it ran a bit smoother afterwards

And just a final thought - have you considered trying you engine in a different chassis? My rusty old Sprinty as plenty quick enough, but when all the bits were transferred into my lovely Moonie, I'm sure it went quicker. I wonder if the conductivity of the chassis changes as it gets older and rustier - you never know....

Good luck anyway - don't give up

Nigel,the post above states i have done all the above mate.

And dont worry i wont give up.

Do you have a current dyno graph? What happens at 5k when it runs ok, is is there a steep increase in power?

Does it do it at even low boost settings?

You didn't mention it above, but have you checked/swapped the cam sensor?

Having done a quick read-up on your ECU, the spark system relies on the cam sensor to decide which plug to fire. Without that signal I am guessing you won't get a spark.....

Erm.... I thought you were talking about the fault condition. But how would it catch fire?

I would say that if there are any limits, as Flea has surpassed the power output of this vehicle with other cars, he would know if that was an issue......

thats not quite true in so much as johns first run was 480bhp with a badly slipping clutch the cars potential is to be well over 500bhp and correct me if i am wrong has flea mapped 2l to more than this?

there are also other big power cars with misfires, though i cant say if they are the same.maybe the owners will join the thread? barbz had the same as johns but lieghton was able to cure it on barbz ..also the fact he has cured the misfire for a while only for it to reocurr lends wieght to it being a mapping issue if you look at that fact from a purely objective perspective..

I had a misfire problem for a long time which couldn't be traced - tried changing absolutely everything. Still not exactly what the issue was but sen the ecu off to flea for.fixing and now all sorted.

I'm sure he's done the same work on your car so.its a.shame your still having problems.

That maybe true and you have done well to make bigger injectors work but you still have a grey area when re-scaling the AFM at certain boost levels so not 100% just yet.

JBT, I'm confused with your description 'pulse earth' - can you be more specific? What are you losing - injectors or sparks?

i think he is losing spark!

JBT - off topic, did you go to Em-tech in nott's to do your course?

i think we have done the same pug course!!

any way back on topic...

Do the stock engine mounts act as an earth in any way? Just wondered if the Vibra-Technics mounts may be reducing the earth path

Its the pulse earth from the ecu to the coil packs.
This is random and irregular throughout the misfire.

Strangely enough if i pull over and stop the car,wait a few minutes and then retry, the earth then breaks to 2 other separate coils.

On the road,it gets worse the higher gear your in to the point where it wont even spool up in 4th.
Yes on the rollers it will boost but then flat-line at a specific rpm.

I've also just thought - if the ECU is shutting down a couple of cylinders (either by spark or by injector) then the ECU must be receiving a signal that it's interpreting as a reason to shut something down. IIRC, the work that Leighton does concerns the fuel and ignition maps - I rather doubt that he will be interfering with in-built safety systems

So - we have to possible causes

1) A component failure that is directly causing the sparks or the injectors to go down

2) A component failure that's telling the ECU to shut down the sparks or the injectors

Have you considered the knock sensors? I remember being told that they are a bit sensitive on the 20vt - I suppose this is where a map COULD be the culprit - if Leighton has given it a bit too much ignition advance, the knock sensor could be telling the ECU to intervene. However, I always thought the knock sensors simply retarded the ignition, rather than shut it down

we'll get there...

your pulse earth description really is pointing to a wiring issue or a coil over-load

Have you considered going for a better coil? The stock items are right on their limits at the kind of power we're producing. When I tried running at 2 bar, I was always blowing the spark out and had to back the plug gap right down

I replaced both the knock sensors and the crank sensor a few months back as this did cross my mind.
i also used OE Fiat parts following an issue with a NG crank sensor.
But that was good thinking Nigel as no one has suggested that yet.

As much as we can compare these cars,no one currently runs the same setup as me.
The power delivery as you can tell from my multiple gearbox failures is so violent and instant.
Even the apexi wont control the boost under 1.3.
With the apexi off it will still spike to 1.3 when in theory the actuator is 1 bar.
So not sure if this power delivery is a contributing factor.

With my electron pusher's (and programmer's) hat on, I can't see a failure mode that will cause intermittent failure of a simple transistor switch on multiple ECUs.

And yet - I can't find anything in the ECU description which suggests it does other than control revs by inhibiting the *injectors*, not the sparks.

I'm sure you've checked for it, but the only thing I can think of that would give that effect on a scope is the spark coils breaking down; if they go open circuit you could see anything on the groundy side from self inductance.

I'm sure that the power delivery is a contributing factor. have you looked into an ignition amp? these are used on all the big power jap cars:

http://www.nengun.com/hks/twin-power

You may have trouble getting one to work with the 5 cl engine though.... would need to be looked into.