NefMoto

Hello.
I apologize in advance if I go on a ramble or I won't be able to keep track of everything. As I've been dealing with issues for at least the last 6-8 months - I honestly already forgot the full list of what I have changed, replaced, fixed etc..

So at first I will introduce you to my car:
It's an 2001 Audi A3 8L 1.8T 132kW (180HP) Quattro with ARY Engine
It is completely bone stock. No delete kits, no remaps nothing. N249, N112, N75, EVAP, SAI is still in place.
I still even have both of my catalytic converters in place and both lambdas (first wideband one and the secondary one as well)

What I already had or did:
When I bought the car 1.5~ years ago it just had an engine swap (long-block) from another A3 (ARY). They rebuilt the turbo at a respectable local place. The engine was washed thoroughly, new crank bearings, cleaned and tested head, etc. Everything around the engine stayed from the original body, nothing was transferred from the donor.
It drove insane, loved it, one of the best cars I owned until then! But after a while I started getting random misfires here and there... and then without me having time to check on the misfires my downpipe's flex pipe split and I started literally burning everything near the firewall (vacuums, coolant hoses, wiring etc..).

Bought a new OEM downpipe, rewired the coil pack loom (wasn't a batched job, I have years of wiring and soldering experience + I referenced the AutoData wiring diagram all the time), replaced all of the vacuum lines that I could find (N249, N112, DV, Vacuum reservoir, to wastegate, etc...). But I still had random misfires..

Okay I thought it's time for coil packs and spark plugs. Bought new NGK iridium sparkplugs and got used red coil packs (didn't need to modify the connectors as ARY already used that type of coil pack). For a day or two it ran very good and then started misfiring out of the blue again...

Noticed that my air/fuel ratio was very erratic so I started looking again for vacuum leaks and air/boost leaks. Lo and behold one vacuum popped off completely from the FPR + the thick hose under the intake manifold (to PCV) was split and had a a lot of oil everywhere. Grabbed my Vape - started blowing into known good vacuum lines, found all leaks, fixed them.. Again for a day or two car runs insanely good and then misfires again.
Fuck it. Bought new coil packs (NGK ones) for around 100 euros and bought new spark plugs (NGK iridium again) for another 100e.. and still misfiring..

Found a local car guy who had a Seat with 1.8T 132kw, he gave me his Bosch MAF to test - for that short ride around the parking lot with his MAF - everything was fine again, couldn't force my car to hesitate under full boost or anything - because of that we were guaranteed my MAF was shot. Bought a new NGK MAF sensor (without the housing) (HOLY FUCK LET ME RANT HOW MANY MAF SENSORS ARE THERE FOR 1.8t 132kw ENGINES?! There are like 30 different OE codes and all are different). I spent a lot of time researching the correct MAF for my specific Car and Engine and I think I got it right.. But after a day or two it started sputtering, sometimes hesitating.. I don't misfire that much now but.....

Last month 'til today:
I thought okay, I have a lot of expertise in IT field, how hard could it be to stop just throwing random new parts to see what sticks and see how I could find out the ACTUAL REASON of my car sputtering, hesitating, sometimes misfiring.. That's how I found this forum (and you guys don't know how glad I am).

Tried using my HEX-V2 Clone (ATmega162) to connect to ME7Logger or NefMoto but no luck.. Got a CH340... no luck.. Bought FTDI R232RL - NefMoto connected, Map read successfully, Checksums good, Wrote map back into the car to test - everything golden, finally I have my true binary (and not random one from the internet).
Created the .ecu definition file from it. created configuration files etc long story short 3 weeks of just trying to get logging working with not luck but still motivated  ;D
Two days ago I was finally able to connect with ME7Logger and actually get a log out - so I wrote a post in newbie category how to do so, did some more WOT pulls, found another vacuum leak (very small one) did more WOT pulls while logging and now I am here.
Couple of my friends that have experience remapping, reading logs and just turbo gas engines over-all are all at loss with my logs and issue.

Issue:
I get sputtering/hesitation but all sensors show that everything's fine.
Heads up: The map has SAI disabled because we were diagnosing my cold start issues, so all these runs had that map, apart from that everythings stock + I now uploaded my OEM Stock map to my ECU with SAI enabled and I'm still facing these exact issues

I have two MAIN issues that are probably related
- On hot engine I get sticky boost (mid or full throttle) it sometimes sticks at around 0.15Bar and then jumps to full 0.6Bar or I get Sputtering/Loss of power mid-pull or just after gear change
- On Cold I get a lot of sputtering and very sticky boost and cold starts are usually a hassle. If the engine starts I can smell fuel and I need to Rev up to atleast 2.5k rpm and then let go for it not to sputter and die.
- Very rarely I get knock and retardation on WOT above 4.5K (but knock is only on one cylinder and the sensor also reads high knock voltage while on neutral just reving up without engine load, so probably my chain is rattling, the sensor was badly tightened or maybe my engine mounts are too shot and resonance from the body of the car gets back to the knock sensor)
(Both logs attached)

In regards of fuel smell after cold start - No, my injectors are not leaking, yes I have fuel pressure. Yesterday I changed all 8 o-rings on my injectors and after pulling every injector out I had fuel dumping on my hands out of the fuel rail. All cold injectors read 12Ω and they are known-good used injectors from a friend that did A3 to S3 conversion. My previous injector was shot and I just replaced 4 at once.

The main sputtering/bogging-down/loss-of-power problem has been logged in file oem-sai-off-Sputtering-LogFromVideo.csv (attached to the post) on time-stamp: 147.550 (Pull between 135 & 160).
And here's a screenshot from that timestamp:
(https://i.imgur.com/8Jz5YsL.png)
Larger image can be found here: https://i.imgur.com/s4z2cgf.png (https://i.imgur.com/s4z2cgf.png)

I thought that it could be a faulty N75 that did not actuate my wastegate properly (also because with N75 disconnected my car is golden, like it drives with 0 issues and it brings tears to my eyes to not be jerky and bogging down every other pedal press) but I tested out three different N75's and nothing changed at all. No difference.

I am also attaching another log which just has random 3rd gear WOT pulls and I think has 3rd to 4th shift with sputtering, but I cannot 100% be guaranteed.
As well as those two main logs I am attaching two very short logs of COLD STARTS (12h overnight). One which the car dies and the other where the car manages to keep itself running

Conclusion:
First of all I just want to mention that I am really very thankful to anyone who reads this full post and actually tries to look into the logs. I know it's a lot of information and doing this for free is not something people like to do, but I'm hoping I will be able to somehow give back to this forum afterwards!

Second of all I also attached both my .bin and .ecu files which were live when these logs were done.

I now tried severeal times to get through this wall of text... but no chance i read all of this.
can you get to the point and say, like a normal person who is not a book author, what has been replaced or repaired so far and what the problem is?
bullet points would be wonderful

I have two MAIN issues that are probably related
- On hot engine I get sticky boost (mid or full throttle) it sometimes sticks at around 0.15Bar and then jumps to full 0.6Bar or I get Sputtering/Loss of power mid-pull or just after gear change
- On Cold I get a lot of sputtering and very sticky boost and cold starts are usually a hassle. If the engine starts I can smell fuel and I need to Rev up to atleast 2.5k rpm and then let go for it not to sputter and die.

Checked/Replaced:
- New coil packs
- New iridium spark plugs
- Vacuums all changed and smoke tested
- 3 N75's tested, no difference
- DV reversed, unplugged, straight to intake manifold - no difference
- Vacuum reservoir still in place, N112, N249 and other stock systems in place, VCDS tested, working (clicking, turning on)
- No visible or hearable leaks or cracks could be found by me
- Intake o-rings replaced
- Injector o-rings replaced

You need to pressure test the car before doing anything else.
Pressurize everything starting from turbo inlet and see if it leaks anywhere.

You can easily make a pressure test kit using some pvc pipe and a tyre valve.

Should I disconnect and plug off any one-way valves or the puck on the intake side before pressure testing? Or if I find a way to regulate the pressure and keep it under 1bar I should be good ?

Use typical 4 cyl.cfg config

As said before, pressurize from the turbo inlet, then you do not pressurize anything on the intake side. Remove the whole intake pipe.

Related unrelated question - due to all the braided vacuum hoses being cracked and local part stores only sell silicone soft vacuum lines - I changed all of them with those. But if I recall correctly the diverter valve especially had a thicker braided vaccum line. Could I have handicapped the diverter valve by running a 3mm silicone vacuum hose? Or because it's vacuum only it shouldn't cause any issues ?

Also, I noticed that if my car goes into soft(?) limp mode where it runs wastegate pressure (or if I unplug the n75) I do not get any of the bogging down/stumbling or jerking no matter how I apply the throttle.
And usually what I see on my boost gauge is that when I get on the throttle (no matter ir WOT or partial) - I can see boost come up to around 0.25bar, get stuck there, car bog downs and then it quickly jumps to 0.6bar and the car jerks forward and then I go into limp mode

Dissasembled the N75 plug (the 90° plastic thing) and found that both of the wires had their shielding stripped and were shorting randomly (from engine vibrations, torque, weather etc) that's why my symptoms were so unstable and random and seemed like I had every possible 1.8T issue at once

I'm still baffled ecu did not trigger any codes for this

Update: now that the roads got cleaned from the snow and I could actually give a try with proper WOT pulls:
- Uneven/Sticking boost issue was resolved
- But stuttering, bogging down and hard cuts are still present.

I also removed my cats as I thought that they might be clogged due to last years bad map (currently running stock) and now I can clearly hear even on low rpm and mid throttle that my engine is not sounding the way it should. It sounds like ... i dont know how to describe it? Rattly, like a tractor.
My gut tells me my timings off, and probably ARY engines do not have CEL's or Codes when timing chain streches or the vvt tensioner is €%#ked.

I am guessing still no pressure test done, which is literally the first thing you should always do on a turbocharged engine.

Little update:
I was finally able to get a garage, with air compressor and some free time to actually delve deeper into this. Replaced PCV valve with the H-pipe. Then I started testing:

- Disconnected Intake from MAF/Airbox and plugged it with a brake-cleaner can
- Disconnected Boost pipe from Intake Manifold and plugged it with a WD40 can
- Removed the PCV Puck from the Intake Pipe before turbo and put a tire valve stem there and clamped it on good.

At first when giving air from the air compressor I saw that no pressure stayed and it quickly went down to 0, so after closer inspection I found a leak where the metal charge pipe (after turbo) connects to the rubber hose before the intercooler (the nasty quick release with an O-Ring inside)
I wrapped the old o-ring with electrical tape, cut out the excess and reconnected everything: Success! I can put in 0.5Bar of pressure into the turbo system and it stays there, no hisses, no bubbling in the oil pan, silence and 0.5bar on the meter.

Great - went out for a drive - still stutters after shifting on high rpm and still got a "Pressure between turbo and intake (Check DV!!)" code..
I re-tested the MAF again and saw 150g/s at 6k rpm, which for 180hp 1.8T ARY is exactly what it has to show. Idl'es at around 5g/s give or take.
MAP readings show exactly what I see on an analog boost pressure gauge connected between IM and FPR so I am not planning on replacing the MAP sensor yet.

Currently I have a "Lambda heater performance too low" so I will try to replace the first lambda sensor (wideband, 6-pin) with an OEM Bosch unit and clean out the plugs under the car and see if a new proper oxygen sensor will provide truth to the ECU and if that fixes my issues..

Update after another 12 hours in the garage..

- I've put in a new OEM Bosch Oxygen Sensor (wideband, 6pin), cleaned the contacts on the plug with contact cleaner, tidied everything up
- I also pressure tested my system again (intake after maf plugged, boost pipe before intake manifold plugged)
- - My oil pan gurgles when pressurising the system and I can see that the pressure is leaving through the valve cover/pcv system?
- - quick google search gave mixed results - some say its normal and should be like that, others say head/valves/turbo gone

Either way, I couldnd find any actual leaks to the atmosphere but I'm still getting the Pressure Difference code. The DV valve holds vacuum, if I keep my finger on the vacuum nipple the valve doesnt drop until I let go.

Oh and with the new o2 sensor im still getting "heater performance too low" and "circuit malfunction" codes.

So.. yippy.. electrical gremlins somewhere along the main wire loom?
Anything I could check before tracing every wire in the car?

When you get any code for the primary 02 sensor it will disable closed loop lambda and only run open loop. Engine loom diagram attached

You did it incorrectly.
Do not disconnect the boost pipe from the intake manifold. By doing that you didn't test any of the connections to the intake manifold and that's where the majority of boost leaks are.
Long story short, you basically didn't test much apart from your boost pipe.

Gurgling is normal because you are not testing post turbo, so some air is going through the turbo oil seals into the oil pan.

Thank you for such a quick reply and for providing the diagram.
From what I've gathered:
Technically the ground would be the downpipe grounding to head to battery?

So my main two interest points would be to either check if my grounds are good and not lose
And PIN 3 Fuse connection (43A)?

I've read online that bad fuel pump relay or some random fuel related loom issues cause o2 errors, especially the "heater performance low" but looking at the diagram I see no way of this being true right?

Can an exhaust leak before O2 sensor trip "Circuit Malfunction" code?

Happy New Year

Another update:

If you think it's not MAF - at the end, it's always the MAF :)
I had way too much trust in all of the many audi/vag forums` replies in regards of MAF values (idle/wot) and was 100% sure that my new MAF was not the issue, and everything else around the engine was the culprit.

This week I bit the bullet and found someone local with a used, oily MAF but from the exact same engine as mine (ARY, vvt, 180hp) and bought it.. and what do you know - All of the stuttering, bogging down and insane fuel cuts at 6k rpm shift - gone...
After almost a year I finally felt what it was like to go WOT from 3rd gear to still WOT 5th gear without ANY hiccups from the engine..

Will button up some more coolant leaks, seal up the exhaust fully where it smokes a bit and do another WOT pull log with ME7Logger..

Before you tune anything, make a proper boost leak test, not testing just the intake, but all the auxiliaries connected to the intake manifold, because 99% of the time that's where the leaks are and not in the part you tested.

I've replaced everything below and after intake manifold which includes the PCV system and smoke tested it. Currently no leaks there, but once I am ready to start increasing boost - these will be recheked and pressure tested first thing

Thanl you for the help