All Things Mk5 > How to Guides / Troubleshooting
Spark plug gaps
pudding:
--- Quote from: AJP on November 17, 2016, 07:47:24 pm ---
--- Quote from: Pudding on November 17, 2016, 07:28:28 pm ---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.
--- End quote ---
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.
--- End quote ---
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?
AJP:
--- Quote from: Pudding on November 18, 2016, 04:42:48 pm ---
--- Quote from: AJP on November 17, 2016, 07:47:24 pm ---
--- Quote from: Pudding on November 17, 2016, 07:28:28 pm ---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.
--- End quote ---
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.
--- End quote ---
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?
--- End quote ---
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.
kuriisenbo:
I should have never bought this car, it has too many issues for my liking.
ClaireSuther:
I feel you man, the DSG is a complete nightmare. I guess he was referring to the case when Volkswagen had to call back a lot of cars due to the scandal with emissions. Plus DSG automatic gearboxes are indeed very prone to defects in the early stages of the car's life and they cost way too much to repair. I have been reading a Jetta forum and I didn't find a single owner to be pleased and want to keep that car. Of course all cars have flaws but no german brand has as many as Volkswagen. You can find a lot of information regarding this issue at https://atfulldrive.com/e3-spark-plugs-vs-ngk.
pudding:
--- Quote from: kuriisenbo on December 09, 2020, 09:40:33 am ---I should have never bought this car, it has too many issues for my liking.
--- End quote ---
Well that's a chunky dose of controversy to drop into a 4 year old thread. Care to elaborate?
Such defeatism these days when it comes to cars. Looked after GTIs have very few show stopping issues. Name me a car, ANY car, that has zero issues?
I know of 200,000+ mile GTis and Edition 30s still going strong with no major repair work, just maintenance. I don't consider that a bad result for the world's first mass produced DI petrol engine.
Maybe you would like an electric car which has one or two moving parts.
Navigation
[0] Message Index
[*] Previous page
Go to full version