2017 vw golf major misfires flooring it

Hey guys im back with another problem. Just took my car to get serviced (Trans fluid) and the techs took it for a test drive. The guy calls me and is like you know you have major misfires flooring it? This is happened before I got an epc and check engine light. When the tech floored it in D, he said check engine and epc came on and car went into engine limp. Restarted car, and drove fine, he clicked it into manual and floored it without any issues He also told me that it would misfire when he heard the woosh sound, hed step on it after the sound… I have an apr stage 1 tune with a bov adapter installed, tech said it could be the bov adapter causing the misfire as its venting into the air. I was thinking it could also be coil packs, I just replaced the plugs but not the coils. What do yall think?
Also spoke to tune shop, they said not the tune itself causing the issue.
61k miles.

Thanks for the help, I’m still learning here.

If you left the factory spec spark plug gap, you might try reducing it. Start with 0.02 inches or 0.5mm. If it improves it a noticeable amount but doesn’t solve it, go another 0.02. If that doesn’t work, post back.

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Yeah currently at .28, found mixed info online. Apr has their recommended plugs at .26 might be worth a shot.

Could also be coilpack idk

Could be, but I don’t think ignition coils go bad that often, especially at such low mileage. In fact, I have owned several cars in my lifetime, many with a single ignition coil and distributor, and not replaced an ignition coil/coil pack ever. At the company where I work, we have several Toyota trucks with over 200k miles, some with over 250k miles, none have had ignition coils/coil packs replaced. There is a diagnostic tool which can tell you if the coil/coil pack is bad.

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Yeah I know they usually last a long while. I was searching through and people said with the apr tunes it can’t create enough spark to burn all the gas you are shooting into the engine. I’m also having my front strut mounts replaced as they went bad so I believe anything can happen with this car now haha.

Also wanted to add, I do have the more “aggressive” version of the tune, 93 octane. Ill see what the shop says, I’m trying to get a general idea and all evidence is pointing to bad coilpacks or plugs.

And the plugs I purchased were the cheaper bosch, $8 a piece.

Ask shop to determine why car entered “limp” mode. Drive-train computer stored diagnostic codes is first place to check. Hopefully a clue to be found there. Since it happened at wide-open-throttle, I’m guessing pre-detonation (engine pinging) was detected. Mixture could have gotten too lean at WOT causing misfires as well. In any event, before replacing/adjustng parts to try to fix it on a trial and error method, instead focus on figuring out what caused the limp mode to happen in the first place.

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Gonna have them figure it out next week. Unfortunately, I got the car around 5 and they closed for the weekend at 5. The code I got in the past was for some ECU fault but that was different. The person I spoke with said that he thinks it might have been too rich. Hopefully its a simple fix.

Code I think I got a couple of months ago was p060c, some ecu code, but that could have changed as the circumstances are different.

Edit: Supposedly coil packs go bad often with tunes

So, tell me what a tune does, technically? Advance/retard timing, adjust fuel mixture. How does that damage coils? If you think a tune damages coils, then change your coils.

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I’m just reading what other people are saying. I was told that it’s common, but I’ve been running the tune for a month now.

I was also thinking the blow off valve adapter might be messing with the maf sensor causing some sort of fault. Misfire only happened when you let off the gas then jammed it again, so when the turbo let all the boost out

Your BOV dumping overboard has no effect on this problem. Just ecause on mechanic suggested it doesn’t make it true. The BOV only operates when the thottle is closed so the turbo compressor doesn’t stall. It won’t set a code or cause limp mode.

Increases turbo boost, adjusts the ignition timing map, and maybe a few other things like cooling fan control. More boost = more power. Increased cylinder pressure requires more spark so a smaller spark gap is needed.

And, what controls boost? An adjustable boost controller? Which a 2017 golf has?

There is a spring loaded poppet valve which is the default boost limit if all else fails. Then there is a solenoid that bleeds off the boost TO that poppet valve. The solenoid is controlled by the ECU to regulate boost by controlling how often and how long the bleed solenoid is open. It can create a flat torque curve by adjusting the boost at various RPM levels to create that. It also can stay open longer for more boost if the “tune” tells it to.

Turbo cars have been this way since at least 1985 (my '85 Merkur had this).

The added Blow-Off-Valve dumps the turbo airflow overboard when the throttle is closed so that when you stomp the throttle the turbo is still spinning rather fast for near-instant boost. You can improve that even more if you inject a tiny bit of fuel into the engine when the exhaust valve is open ignite and boost the exhaust turbine to enhance response. It is really hard on the turbo, though.

Could have caused my computers to go nuts. The adapter I have is 100% vent.

I’ll pop the adapter off and see what happens. Some people said bov adapter, which isn’t a bov it’s just a hole, doesn’t mix well with maf. If that’s not the case I’m gonna get The apr coil and spark plug kit. .24 gap

No it won’t cause the computer to go nuts. Factory BOVs vent back to the airbox forcing the MAF to read it again.

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I understand now, most likely bad plugs or coils , seems to do it when you really floor it