Fueling Issues (Logs/Measuring pics included)

[djtronik]

Hi all,

I have been fighting what I think I have pinned down to be a fueling issue. To sum up mods as best as I can, the car itself is running Unitronic's big turbo setup, MAFless tune (yeah, I know..I bought the car this way :/) with built motor, Precision 5558, IE internals, RS4 injectors, upgraded HPFP, external waste gate, blow off valve etc. So here's the issue:

The issues I have:

When hitting about 2K RPMs in any gear besides first gear, car is surging in RPMs and shaking, not accelerating
Rough idling, eventually kind of improves after letting it sit for a while
Poor acceleration/throttle response
Misfiring of some sort
According to VAGCOM, low fuel pressure I think...please look at photos below

Things I have tried:

Replaced plugs/tried adjusting gapping
Replaced all 4 coilpacks
Checked/replaced cam follower
***I bought a new fuel filter and will be replacing that in the next day or so, but have not yet

Here are my logs with codes the car is throwing: (the circuit code is normal because of the setup of the car, according to previous owner)

Chassis Type: 8E (8E - Audi A4 B6/B7 (2001 > 2008))
Scan: 01 02 03 08 09 0F 11 15 16 17 18 25 36 37 45 46 55 56 57 65
67 69 75 76 77

VIN: WAUDF78E78A024193
-------------------------------------------------------------------------------
Address 01: Engine Labels: 06F-907-115-AXX.lbl
Part No SW: 8E1 910 115 G HW: 8E0 907 115 D
Component: 2.0l R4/4V TFSI 0010
Revision: 5EH15--- Serial number: XXXXXXXXXXXXXX
Coding: 0104010A180F0120
Shop #: WSC 66565 257 00032
VCID: 264310139112D62ECEF-8073

3 Faults Found:
000051 - Turbocharger Bypass Valve Control Circuit
P0033 - 004 - Malfunction / Open Circuit
Freeze Frame:
Fault Status: 01100100
Fault Priority: 2
Fault Frequency: 4
Reset counter: 255
Mileage: 150454 km
Time Indication: 0

Freeze Frame:
RPM: 197 /min
Load: 59.6 %
Speed: 0.0 km/h
Temperature: 56.0°C
Temperature: 40.0°C
Absolute Pres.: 990.0 mbar
Voltage: 10.160 V

000768 - Random/Multiple Cylinder Misfire Detected
P0300 - 001 - - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 151239 km
Time Indication: 0

Freeze Frame:
RPM: 4433 /min
Load: 100.0 %
Speed: 95.0 km/h
Temperature: 80.0°C
Temperature: 8.0°C
Absolute Pres.: 970.0 mbar
Voltage: 13.589 V

000769 - Cylinder 1
P0301 - 001 - Misfire Detected - Intermittent
Freeze Frame:
Fault Status: 00100001
Fault Priority: 2
Fault Frequency: 1
Reset counter: 255
Mileage: 151239 km
Time Indication: 0

Freeze Frame:
RPM: 4433 /min
Load: 100.0 %
Speed: 95.0 km/h
Temperature: 80.0°C
Temperature: 8.0°C
Absolute Pres.: 970.0 mbar
Voltage: 13.589 V

Readiness: 0000 0100

Pictures of measuring blocks regarding fuel pressure:

[EvolutionArmory]

3 things that jump out at me right away is MAFless tune, RS4 injectors and a BOV. Who built this car and were the running issues disclosed to you when you bought it?

[EvolutionArmory]

And have you considered running a MAF, buying S3 injectors and running someone else’s tune?

[djtronik]

And have you considered running a MAF, buying S3 injectors and running someone else’s tune?

At this point, I'm so disgusted I would probably sell the car before doing that. An MAF most likely may not fit into this car anyway because of the turbo they put on it. And the car had no issues when I bought it. The car actually had a build thread on here: https://www.audizine.com/forum/showt...s-Build-Thread

[EvolutionArmory]

Maybe focus on fixing the P0033 code. How is boost being controlled on this build? Is there still a factory like N75 valve controlling boost?

[EvolutionArmory]

And post 91 in that thread says he was waiting for Unitronic to perfect his tune in 2013. Did that ever happen?

[djtronik]

Maybe focus on fixing the P0033 code. How is boost being controlled on this build? Is there still a factory like N75 valve controlling boost?

I'm running out of ideas there. And no, BOV/external WG. And yes, the car apparently seemed to have had a custom tune done for it according to what I was told.