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Misfire.


tony tt
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30 minutes on a dyno with diagnostics attached would show the cause, if the logs don't point a finger at anything. Can you log the wideband, that would give a good clue?

 

Looks like I've no option but to pull logs and send to Ryan. Doesn't seem that anything I buy will cure it and I don't want to keep spending money on parts I don't need.

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i know the syvecs will not let you create boost if it thinks there is a potential problem, now with you being able to feather it in the ECU may think this is fine, but if you want ALL the power it could be going no chance, and yes protecting the engine.

 

we will need to clear logs, then pull logs after some hard pulls and see what it then brings up?

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i know the syvecs will not let you create boost if it thinks there is a potential problem, now with you being able to feather it in the ECU may think this is fine, but if you want ALL the power it could be going no chance, and yes protecting the engine.

 

we will need to clear logs, then pull logs after some hard pulls and see what it then brings up?

 

I can understand that just don't get why it will boost like a train for a while then it says F##k you all of a sudden. It's a weird one.

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I don't know mate I've never ran Syvecs before. Quite possibly after the hour or so it being ok it shuts down and doesn't allow full boost when it's floored.

 

Does it feel like you're hitting the rev limiter when the misfire occurs? There should be lots of pops 'n bangs if so.

 

Might also be worth checking the main harness to the coils for cracks/wires arcing out. If you see anything suspect, insulate them. I would also check the plug to the MAP sensor and also your cam sensors to see if they're all pushed on all the way and fixed securely in place. It's easy to miss silly little things like this.

 

As Chris has said, a Dyno session is the way forward, but there's no harm in trying the above if it's not convenient for whatever reason.

Edited by Big Supes (see edit history)
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I don't know mate I've never ran Syvecs before. Quite possibly after the hour or so it being ok it shuts down and doesn't allow full boost when it's floored.

You can email me the logs if you want and I can tell you if it's tripping, but the easiest way is wait until it happens, switch the car off (key out) then start her up and give it a bootful. If it drives properly, the engine had more than likely trip. It'll come back quite quick though after giving it a bootful. PM sent with email address :)

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Confirmed the car goes into limp mode. I did unplug the map sensor and plug it back in so I'll see how that goes later when I take it out again. Sat and free revved the car after I got back and it's holding at 4500rpm won't go any higher.

 

- - - Updated - - -

 

Just had a similar issue with my map sensor if u need advice as limited as i can give you ill do my best .

 

 

Was it a faulty sensor bud?

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ok just back from doing some runs with tony and pulling logs, who can red these? tried to put them on here but the file extension the forum does not like.

 

when the car pulls hard we can see a problem with Cyl 2 it goes read on Sview(and the numbers are up high at 10's) from here it gradually comes down, then goes white. Looks also there is a problem with Lamd1.

 

I've got the files here just need someone to email them too, to make heads or tails of it.

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From what you say it looks like a cylinder two misfire though. Nip up the connectors (NOT the plastic connector bodies people obsess over, the actual metal terminals within the bodies), so they are a good tight fit on the male spades in the coil packs. Try again. If it's the same swap No 2 plug with say number 4 plug and try again. If the problem moves to cylinder 4 then it's the plug. if not it's perhaps the number 2 coil pack itself, so swap that with the middle coil pack, see if the problem follows the coil pack. If not check wiring from ecu to ignitor and ignitor to coil pack very carefully. Caveat, this is what *I* would do, a mapper might be sniggering as I am NOT a mapper... It could be an injector issue, so you could sap number 2 injector with say number 4 and see what happens, also check injector connectors very carefully. Swapping stuff is crude but cheap. An oscilloscope (my favourite diagnostic tool these days), should be able to show the issue in real time.

Edited by Chris Wilson (see edit history)
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