Sounds like a momentary lean condition. The transient fuel demand when flooring it after a gear change can be pretty huge.
Either that or something is amiss and the ECU is pulling back. Over boosting maybe? Anything revealing in the logs? As always, best to use VCDS in turbo mode.
Did some logs a while ago before the refurbed injectors went in (and the misfire was really bad) and the car behaved itself so left us clueless.
Since fitting the injectors it's like a different car... apart from this very rare but specific hiccup which manifested after the injectors went in.
I don't have VCDS, and even if I did I'd be waiting weeks or months for it to happen again. It seldom happens. I don't know if the fact I'm still on a Stage 2 map but with a Loba pump has any bearing on it, but logic tells me that if anything I should have more fuel headroom than if I was on 2+, so I doubt that.
I know I'm just guessing without doing more logging though. Although if it was momentarily overboosting like you suggest then it might have stored a code.
Not always. An event the ECU doesn't like needs to happen a bunch of times before it logs it as a fault. Unless of course it's a wiring/sensor fault, then it's logged immediately.
When I was fitting my downpipe, I'd disconnected the battery. So the first few times I went into boost again afterwards, the ECU majorly threw a fit and pulled it back.....like hitting a wall as you say. A big time overboost as it felt way quicker than usual before the ECU pooped the party. No fault codes! It's been fine ever since it's relearned and sorted itself out.
Occasionally I'll get a stutter in 6th when flooring it from 2500rpm after a period of cruising. Pretty sure it's not coils or injectors as they were new not long ago. Standard car didn't do it, so it could be a glitch in the map for that specific load scenario. I've been meaning to get to my mapper for ages, just can't find the time!
A dyno might be the only way to troubleshoot it. Nothing was spotted during your mapping?
Yep that's why I said 'might' as it's happened a few times now so could be enough to store a code, although it's a bit optimistic. Live logging while it misfires would be ideal but it's not the most convenient thing.
Mapping was fine, the only comment from Niki was that it was struggling a bit for fuel in the midrange. I subsequently got some fuel cuts, as expected, then fit the Loba pump which sorted that. Then came the really bad misfires under load which were eventually sorted with refurbed injectors (initial change to new coils and plugs didn't work). Things have largely been fine since then except for this one little hiccup going from 3rd to 4th.
I should really be on a 2+ map by now but the way I see it the car should have plenty of headroom running mostly 2+ hardware on a Stage 2 map. I'd expect problems if it was the other way round.
Steve at Statller did say the map was "pushing a lot of timing" or words to that effect. I'm not sure if that was deduced by the logs I sent him in the summer or just by driving it.
The only reason I haven't gone down to Hinckley for the 2+ update is that I'm hopefully going k04 soon, so it'd be pointless.
