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05micablue
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Why would you replace the spark plugs?

 

If you replace the intercooler with a stock one, without bulletproofing it, it'll just leak again. Some options, in ascending order of cost:

a. Bulletproof the existing one, if it's recoverable

b. Buy a bulletproofed one

c. Get a new stock one and bulletproof it

d. Buy an aftermarket one

 

Moving on to the codes, the P2021 is the primary. It indicates a problem with the tumble generator valve on cylinders 2 & 4. This may or may not be causing the misfire on cylinder 4.

 

This is what you should work on first, then the TMIC.

 

Start on page 2144:

http://people.csail.mit.edu/ilh/vacation/

You should be able to use BtSsm to perform the test in step 1 of the diagnostic procedure.

 

Can you post LV from BtSsm? That'll give a good idea of the severity of the TMIC leak.

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I'm only pushing MAYBE 10.5 psi at WOT. I also just called a reputable shop, and was told that a boost leak will make the 5k fall-on-its-face issue happen, and that the misfire may be related.

 

I will check that website out and report my findings. Ordering cable tomorrow.

 

Expect results on Sunday.

 

Edit: The intercooler is stock, just an FYI.

 

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Dude at O'Reilly had one, not I, and I'm under the impression you can't flash a tune with those either.

 

Should I order new TGV sensors alongside a new top mount tomorrow and a cable, just in case?

 

I'm going all aluminum for the tmic

 

I'll take your advice and leave plugs alone.

 

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So, unrelated, but up-pipe and downpipe are stock. Exhaust is a Magnaflow catback. I crawled under and actually looked instead of taking someone else's word.

 

Cool beans.

 

Just giving as much detail as I can.

 

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Flat on face and knocking at 5k sounds like a fuel pressure problem. These use boost as a fuel pressure booster

 

The first(easiest) thing I would look at is your "fuel pressure regulator" or whatever-the-crap its actually called. When I got mine protuned, the Vac line going from the side of the intake manifold to the fuel pressure regulator blew off under load. At 4.5k ish or so rpm my fuel trims went way lean as the fuel pressure couldn't keep up. That would very easily kill an engine if it kept up. It's behind the battery mounted to the body, and its maybe a 8" vacuum line. Super easy to see once you look in the right area. Remounted and ziptied= no more fuel issues at high rpm.

 

And also check for other boost leaks. I'd Ziptie the crap out of your T connector (under the intercooler, small black T that connects to the BPV) and every other vac line you can reach while the TMIC is off.

 

While it's off, you might be able to throw your hand on the turbo inlet as well, see if that's sealed right. It shouldn't cause low boost, but it will be a big leak that can be hard to find and easier to see with the IC off

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No problem! When I got my car back from the dealer for a warranty Engine/turbo replacement it wasn't quite running right, ended up pulling the intercooler and went ham on the vacuum lines.

 

I didn't have any issues with my boost control system, but I did find a few issues nearly everywhere else. Low and inconsistent boost could be broken/disconnected vacuum lines going to the turbo/wastegate. There's 3 lines iirc. Those ones are a little harder to see, but it would be worth it for piece of mind to look up a vacuum diagram and inspect/ziptie everything while the engine cover and ic are off.

 

I'm going off of memory here, but I think* normal fuel pressure on a oem fuel pump is 40 ish psi, and at higher rpm it needs 40+boost to keep fuel needs met.

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That makes sense. Because its obviously leaking from the intercooler, I have one on order, so I'm replacing that to start off with.

 

I have my VAG-COM coming in tomorrow, I will pop open the laptop and check out my fuel trim and pressures and all that jazz.

 

I'll let y'all know what I find!

 

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Okay. So I know I was told not to. But I kept worrying about my misfire on cyl 4.

 

I changed both driver side plugs, and I'll get to the others tomorrow. Swapped the two driver side coils, if the misfire follows the transfer, I know what's up.

 

Cleaned and resealed the MAF too, while I had it apart.

 

Plug was really grey, too, btw.

 

I've gained 1-2 lbs of boost so far, and it feels heaps better through the rev range. Still falls on it's face at 5 grand, so I'm hoping to look at fuel tables tomorrow, maybe datalog on my way home for you guys, or some time this weekend.

 

Intercooler shows up Monday.

 

I know I'm not done, but it feels like a different car.

 

Thanks all

 

 

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41002922d144cb32616d2f84bd2d7a62.jpgd5d0c94c8f8912081d45161257520d5a.jpg

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Can't wait!

 

I assumed it was running rich because I could smell it. Turns out it was just dumping raw fuel out of that cylinder.

 

I'll get that program installed tonight and make sure it all works.

 

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Edit: Here's the the plug for cyl 2f7032b66ae0c55b5b38d14a561bdb7bc.jpg

Edited by 05micablue
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I can do that!

 

I was thinking valve drop or head gasket.

 

I'm fully prepared to swap this motor if need be. I don't want to but I will if I have to.

 

Swapped the #2 and #4 coil packs and it didn't move, so I'm ruling that out

 

 

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