[rusEfi] 2006 Volkswagen Passat 2.0 Turbo GDI test mule #64

[kb1gtt]

These scope traces were captured on the same but different engine. It was N31 Cyl2, the green with black wire. Current clamp was a Rigol RP1002C on a Rigol DS1054

[AndreyB]

If things go well will finally have GDI test mule at my garage tomorrow.

https://www.patreon.com/rusefi funds would get new battery and first order of business fixing the door handle.

[AndreyB]

[mck1117]

Science has been happening to calibrate our mc33816 dev board to drive these injectors!

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[AndreyB]

It starts and then it dies right away. It had new battery and full tank, it was parked for two months. No codes on simple OBD reader.

[AndreyB]

^^^ that was a funny one.

The intake pipe has split into two pieces nicely opening access to unmeasured air. Fixed with duct tape for now.

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[AndreyB]

Bosch Quick start VVT tested on real hardware

https://rusefi.com/online/view.php?msq=205
https://rusefi.com/online/view.php?log=30

Open question is what's the next GDI step

[AndreyB]

This test mule Passat takes up very valuable space in the garage, it cannot just sit there. I will try to make whatever progress I can make on my own but I am concerned that this project could be way over my head. If the next month turns out to be pointless head banging I would have to stop. At the moment I really need GDI help or I would have to give up and get rid of the car

One of the source of inspiration could be OEM tables but are those always named in German?

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[AndreyB]

https://vasyadiagnost.com/ is like VCDS but Russian. A nice box, license key and stuff for $75.

[AndreyB]

So ^^^^ has produced attached log

Groups 101 - 109: Fuel Injection does not match Russian translation precisely but is kind of close.

mechanical translation says

Code: Select all

Sunday, 11, October, 2020,21: 10: 48: 10463-VCID:, Software version:, Protocol type: troubleshooting
3C0 907 115 F ,, 2.0l R4 / 4V TFSI 0030,

, Group A:, '101 ,,,, Group B:,' 103 ,,,, Group C:, '106
,, engine speed, engine load, Injection timing, Mass Air Flow, current, fuel pressure, adaptation value, Fuel pump Adapt. ,, Fuel rail, Electric fuel, Electric fuel, Fuel pump
, TIME, (G28) ,,, Sensor (G70), TIME, fuel pressure, regulator, fuel pump, Status, TIME, pressure (actual), Pump 1/2, Pump 3/4, Trip Time
Marker, STAMP, / min,%, ms, g / s, STAMP, mbar ,,,, STAMP, bar,% ,, s

On idle looks like 1.28ms injection time and 3.2 g/s MAF reasing
I believe I see 50.6 bar low high? fuel pressure, 49% pump duty maybe?
I do not really get 4189 mbar what is it? 4bar low pressure?

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[AndreyB]

At this point I have exactly zero information on how low pressure pump is controlled. Any hints would be appreciated!

PS: wiring plan

4 for SPI, plus 7 more
RSTB and DRIVEN on lowside outputs (with pullup), and the injector outputs on extra pins direct to mcu maybe hopefully, would need to do exact pin counting

[mck1117]

stick a scope/meter probe in the wires from the ECU to fuel pump control module?

[AndreyB]

https://www.drive2.ru/l/565601151907528941/ has images of naked fuel pump control images. "self-education VW 334" is mentioned

How it works
The electric fuel pump always conveys as much fuel as
the engine requires at a particular time.
The momentary fuel pressure is measured by the fuel
pressure sender for lower pressure and sent to the
engine control unit. If this pressure deviates from the
reference pressure, the engine control unit sends an
appropriate PWM signal (frequency 20 Hz) to the
fuel pump control unit. The control unit sends a PWM
control signal (frequency 20 kHz) to the electric fuel
pump until the fuel pressure returns to the map curves.

http://www.volkspage.net/technik/ssp/ssp/SSP_334_d1.pdf

[AndreyB]

Progress without head banging is my favorite progress!

[AndreyB]

OEM low fuel pressure poking:
car not running 5 bar, 2.0volts - increased low fuel pressure to facilitate start
car idling 4bar, 1.7volts

which gives us expected 0.5v at 0bar and looks like a 200 psi low fuel pressure sensor?

[AndreyB]

Official https://github.com/rusefi/rusefi/wiki/oem_docs/VW/2006_Passat/VWUSA.COM_SSP_222_Electronically_Mapped_Cooling_System.pdf does not contain enough details about Electronically Mapped Cooling System but https://golf2lin.wordpress.com/features/radiator-fan-control/ fills the gaps

The J293 controller incorporates a failsafe mode where, should there not be a recognized PWM signal of between 5% and about 95% within 10 seconds after 12V is present on its engine alive KL_15 terminal, it runs the pair of fans at full speed. This is nice to have.

The nominal ranges are expressed as:
~15% ≤ low speed ≤ high speed ≤ ~95%

[Abricos]

low fuel pressure sensor

Previous Revisions
06E906051E
06E906051J
06E906051K

Screenshot_20201020-092426__01.jpg

[AndreyB]

Thank you, great link http://rush.smolly.nl/changes/change4_2.htm it has some sweet info! Now preserved in a PDF just in case

[AndreyB]

low pressure fuel control: http://nefariousmotorsports.com/forum/index.php?topic=18584.0title= says

Open loop. KFNTBKS and KFFLAF control the pressure request > duty cycle conversion.

also http://nefariousmotorsports.com/forum/index.php?topic=4996.0

KFNTBKS "Target pressure as a function of temperature HDP"
KLPSKRMX "Characteristic set pressure fuel low pressure system maximum"

Now looking for help to actually see those.

[AndreyB]

Getting closer

[AndreyB]

OEM low fuel tables, next step would be to understand those

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[AndreyB]

I was able to run for a second or two with high pressure pre-build by OEM ECU. Rail pressure vs injector flow table would be nice, as is I am totally blind.

https://rusefi.com/online/view.php?msq=247

[AndreyB]

Ola says RKTI is the relevant chapter
Matt says
korrektur bei variablem kraftstoffdruck is reciprocal pressure compensation

0.03 means 1137cc/min
34.125/KRKATE = cc/min

Looks like injectors are 300cc/min at 6 bar

https://s4wiki.com/wiki/Tuning#Primary

More details to follow.

[mck1117]

with help of @960, we've figured out what the stock injector calibration looks like.

The parameter KRKATE defines the injector flow at a particular reference pressure, which in this case comes out to 1214 cc/min at 10 MPa (100 bar) fuel pressure.

The table labeled Korrektur bei variablem Kraftstoffdruck (correction for variable fuel pressure) contains a mapping from fuel pressure (MPa) to reciprocal correction factor from the reference flow. So at 10MPa it indicates 1.0 (no correction), and at 3MPa it indicates 1.826, which means the flow is 54.8% of the reference flow, so 665 cc/min.

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With some math in excel, we can confirm a few things:

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1. These injectors are identical to the injectors in the 2013 Ford Focus ST (that I used to own)
2. The curve follows a perfect square root vs. pressure relationship, as is expected. Flow thru an orifice is proportional to the square root of the pressure.
3. rusEfi doesn't need a full fuel pressure vs. flow table: we can simply use a reference pressure/flow, and convert on the fly using sqrt.

[AndreyB]

Blue crank VR positive.

Pink high side which is shared between cylinders 1 & 3 - tomorrow I shall move to negative side wire so that we have engine cycle.

Yellow is fuel pressure regulator valve, i.e. HPFP valve. Right now it looks like only one cam lobe is working. https://github.com/rusefi/rusefi/wiki/oem_docs/VW/2006_Passat/SSP_334_d1.pdf is advertising two lobes on the cam so this stock ECU might be skipping pumps on low load. Tomorrow I shall floor this in neutral and see if we get 2nd lobe to pump.

[mck1117]

Yellow is fuel pressure regulator valve, i.e. HPFP valve.

And the important thing here is that it looks like this is a high impedance solenoid, not a low impedance one like some other GDI setups. That means the pump can be driven from a normal lowside output, not something special on the MC33816/PT2001 board.

[AndreyB]

HPFP: On start we seem to be pumping on each of the three lobes and a bit later we only use one out of three lobes on idle.

With all the multitasking still hoping to floor this but tomorrow again.

[AndreyB]

It's November 2020 and I have finally learned how to undo VAG D-connectors - you have to push those IN and then you can unclick.

This dude just talks and talks and talks but he is the source of wisdom.

[mck1117]

This knowledge has changed my life and I don't even own any VAG products.

[kb1gtt]

Yeah, the old push before you pull, that's huge with those connectors. I often give a dab of WD40 to help break them free on the push.