1.8T "Stage 3" swap running rich

Hey. Im finishing my Mk1 Golf 1.8T build here.

The problems im still facing is the fact that, the car is running very rich (all the time - from idle to limiter).
Also while driving and pushing down the clutch it wont idle right for the first like 5seconds or so.
Rpms humm between like 400-1000 for a while until it settles, car wont die tho.
Plus my garage floor and walls are covered in black soot (and little bit of water?) from exhaust once I rev it a little bit.

Here are the mods :
1.8T -98 AEB (DBC)
TFSI Red Coils
GT2860RS
440cc Bosch Green Giants
3" MAF housing w/ AEB sensor
3bar FPR
NGK BKR7E (0.7mm gap)
"Stage 3" tune from Reflect Tuning - made for those mods.
Polo lift pump in tank and Bosch 044 inside swirl pot in the engine bay. (Lift pump just keeps it topped and 044 circulates between swirl pot and fuel rail)

So…When I got car started for the first time and I went for the first test drive (~60miles) Im pretty sure it idled just fine back then and pulld like crazy.
Soon after test drive I pulled the plugs and all four of them lookd exactly the same. All fouled, not wet but black.

I had time for dyno (not for adjusting. I just needed sheet for MOT to make this thing road legal) and there we pulled our my O2 sensor and put in wideband - AFR 12.0 @ 2000rpm, AFR 9.9 @ 6200rpm.
Made "only" 275hp from the wheels since it was so rich.

In idle my short time fuel trim says -29.7%, fuel injectors average time 1.98sec, air mass flow 2.8 g/s

Im not getting any fault codes. I think they are coded out or something.
I did get some fault code when i unplugged my O2 sensor tho.
Also I unplugged my MAF once when car was idling and car died instantly. Cranked it up again and it fired up, but again would die the second i lifted the gas.

What I have done this far:

I have replaced MAF (Bosch), O2 sensor (Bosch), Coolant temp sensor, FPR, DV.
I made boost leak test and found couple leaks and fixed those, but didnt make difference.
Sprayd all vacuum hoses with carb cleaner, didnt find anything.
Measured fuel pressure, ~3.25bar vacuum disconnected, ~2.85bar vacuum connected (at idle).
I sended my injectors out for flow test / service last week. Should get those back later this week.

Couple things that still comes to my mind :

My all 4 coils are cheapish copys, should I get better ones? - im not aware of any missfire tho.

I havent changed IAT sensor yet, since values seemd normal to me (~20c-30c if i recall)

I ordered compression tester and cylinder leak tester. Going to give those a try after they arrive.

I still have those ~80 miles old plugs, even theyr fouled. Should I get new ones or just clean these?

Any other ideas are more than welcome !!

I'm no tuning guy but i got a couple of thoughts..

Cant see it being the coils, if its not misfiring - leave 'em in. Same with plugs, bit of soot wont hurt.

Have you checked engine coolant temperature on live readings? Is it getting up to temperature, thermostat working etc? obvs if its running cold or the sensor is reporting -40 or something it will run rich.

If i'm understanding this right, you have had a remap but have changed parts afterwards? I would say it probably needs mapping on a rolling road to get it perfect.  

Coolant temp sensor live readings are ok (im using Obdeleven).
Thermostat and radiator fan etc works as intended.

Yeah, I bought this ECU from over seas, so its not tuned based on my car, but rather I bought mods based on this tune.

Yeah tune is one thing im considering that could be the problem. Just want to rule everything else out first, since this kind of tune for older AEB engine is going to be very expensive here.

One other thing im thinking would lowering my fuel pressure help? If i get 1-5 bar adjustable fuel pressure regulator and drop it to around 2-2.5 bar ?

Who are Reflect tuning? And does the ECU operate in closed loop mode? Everything is pointing at the ECU being wrong.

Reflect tuning is company based in the USA.
The guy that makes these tunes is also known as k0mpresd on some other vw forums.

As far as I can tell its operating in closed loop mode. At idle if STFT is -29.7% and if i give it a little bit of gas, it goes up to 0% for a while and then slowly drops down to -29.7% again.

I dont know if there is differences in M3.8.2 and M5.9.2 ECU's ?

My original ECU was 8D0907558E (M3.8.2) and my new one is 8D0907557P (M5.9.2).

Do they use different sensors or is wiring different or something ?

GOL1 said

 and there we pulled our my O2 sensor and put in wideband - AFR 12.0 @ 2000rpm, AFR 9.9 @ 6200rpm.
Made "only" 275hp from the wheels since it was so rich.

Firstly if you pulled out your O2 sensor, what is the ECU then using, or is it effectively operating in a degraded (because there's no O2 sensor), open-loop mode?

Secondly what load are the measurements at, at 2000rpm and 6200rpm? You could expect more or less stoich at low-mid load, then gradually lower AFR to about 12 (or maybe a bit more, or less - don't take 12 as gospel) at upper rpms and wide open throttle, full load.

Either way, it definitely sounds like the ECU or some sensor which is feeding it information. Does it have normal ODB2 capabilities, ie can you correlate ALL the relevant sensor voltages to physical values eg mass air flow, fuel pressure, AFR etc etc. Can you engage in dialogue with the provider of the ECU and get a bunch of sample tests to do, to see what's going on? And can he re-do the program and you flash it onto the ECU or is it a return to USA job?

Im no ecu expert. Dont know if it goes to open-loop or only use maf data if other fails.
Got P0134 (O2 Sensor circ. bank1 - sensor1 = no activity detected) and P1196 (bank1,sensor1, heater circuit = electrical malfunction) when I pulled O2 sensor off at dyno.

Dont know what engine load is during pull.
I do have OBD2 and i can watch live data etc, but with my obdeleven for some reason I cant log graphs with this ecu like it should and I dont have laptop for vcds…

I dont have any experience in flashing ECU's, so if I wanted this same guy to make changes to tune I would prob need to send this ECU to States…

Ok you still don't have any usable data. You need to be able to measure the AFR (using a wideband lambda) while the O2 sensor is plugged in, because it sounds like its able to adjust it properly. Disconnecting it then using the wideband gave meaningless results so they can be ignored for now. At least its in the right ballpark and the fuel trim is able to adjust for it.

If its on a rolling road then it sounds like it was an almost-full load run. Which is handy. But for a decent map, you'll want to check all the bits in between too; and during warm up.

That is correct.
But still, im having fouled spark plugs (all 4 of them) and STFT -29.7% with O2 plugged in - indicating rich conditions.

If my leak down tester doesnt show massive leaks, if injectors turn out to be okay and I cant find any boost or exhaust leaks is it safe to just turn down fuel pressure abit ?

Since this thing isnt road legal right now, and only reason I havent went to MOT yet is becouse im pretty sure im not going to pass HC emissions with rich idle.

And also… This car have been work in progress for 2 years now. So the gas in the tank is also 2 years old. Dont know if that could cause problems ? I think that it would rather gives lean conditions tho.

You can't go off fouled plugs. If the short term fuel trim is -29% the ECU IS adjusting the mixture to try achieve lambda=1. Maybe its a bad O2 sensor and its adjusting, but to a rich mixture not a stoich mixture? That's why I said before, look at the RAW data (ie sensor voltages) and see if its plausible (or stuck at one end or another)..

As has been already said, you need to be able to properly (so you know 100% for sure) measure the mixture, with everything plugged in and the ECU throwing no codes.

Then you need to talk to the supplier of the custom ECU.

If you adjust fuel pressure, the ECU might just compensate for this and send the mixture rich by turning up the injection duration, after all.

GOL1 said

That is correct.
But still, im having fouled spark plugs (all 4 of them) and STFT -29.7% with O2 plugged in - indicating rich conditions.

If my leak down tester doesnt show massive leaks, if injectors turn out to be okay and I cant find any boost or exhaust leaks is it safe to just turn down fuel pressure abit ?

Since this thing isnt road legal right now, and only reason I havent went to MOT yet is becouse im pretty sure im not going to pass HC emissions with rich idle.

And also… This car have been work in progress for 2 years now. So the gas in the tank is also 2 years old. Dont know if that could cause problems ? I think that it would rather gives lean conditions tho.

If you ordered a precoded ecu they will have probably made it run rich for safety to cover themselves as you may know running lean is super dangerous. If you look at a lot of tuner cars running big turbos they tend to run rich and kick out a bit of black soot.

As for the gas, cant see that making it run rich.

She needs mapping on a dyno to fine tune, It sounds like youve done all the right things on the mechanical side, you've tested for leaks and found non, its firing on all 4 cylinders, not much else it can be.