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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Thu Oct 22, 2020 5:37 am
by AndreyB
Getting closer
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Thu Oct 22, 2020 4:54 pm
by AndreyB
OEM low fuel tables, next step would be to understand those
image.png (173.49 KiB) Viewed 63685 times
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Fri Oct 23, 2020 4:56 am
by 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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Fri Oct 23, 2020 10:14 pm
by 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.
image.png (146.2 KiB) Viewed 63643 times
With some math in excel, we can confirm a few things:
image.png (23.61 KiB) Viewed 63643 times
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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Sun Nov 01, 2020 5:15 am
by 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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Mon Nov 02, 2020 4:26 am
by 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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Fri Nov 06, 2020 8:03 pm
by 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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Fri Nov 06, 2020 8:09 pm
by mck1117
This knowledge has changed my life and I don't even own any VAG products.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Fri Nov 06, 2020 9:57 pm
by 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.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Mon Nov 16, 2020 5:12 am
by AndreyB
I've somehow destroyed two injectors, #2 and #3 (those share boost line - GDI setups have injector pairs share some of the electrical magic).
I have no idea how this happened and that's the scary part I read infinite resistance, stock ECU is misfiring, stock ECU throws injectors #2 and #3 codes after about 10 seconds.
Damn. Internet says it's a couple of hours to replace, I've ordered a kit of useful special tools, I have spare injectors but I wonder how many more spare sets I would need
I believe I have polarity right. I do not have any other ideas what I could have messed up.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Mon Nov 16, 2020 5:51 am
by AndreyB
Looks like a LOT of fun to replace those injectors
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Mon Nov 16, 2020 10:38 am
by kb1gtt
While your at it I suggest changing the oil prosper switch. It's cheap and a bigger to change. I also understand the injectors will be stuck. You might want to consider just breaking then all out and replace them. I understand even with the head off they are difficult to get out.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Sun Nov 22, 2020 5:04 am
by AndreyB
Low pressure fuel control works:
For whatever reason GP4 low side did not seem to control low side fuel pump module (reminder that on this vehicle there is a small control module between ECU and actual pump module takes 20Hz control signal from ECU). Thing got better once I've started to use TLE8888 "injector 4" channel for low pressure control signal.
yellow line HPFP valve, pink line coil #1 signal. One image stock ECU another image rusEFI looks close enough to build something?
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Sun Nov 22, 2020 4:19 pm
by AndreyB
Actually those images above show a problem: there is no 12v feed into HPFP valve any more
On OEM image we see 5v scale and 2.5 bars for 12 volts swing. On rusEFI image we have same 5v scale but only 3v of swing
I believe that https://github.com/rusefi/rusefi/wiki/VolkswagenPassatB6 point at fuse F33 15A. I've opened the fuse box - fuse is fine but there is no +12v on the "source" terminal?! I.e. I now have a damaged fuse box? Makes no sense
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Sun Nov 22, 2020 5:54 pm
by AndreyB
Bingo! With one more relay energized I have high pressure fuel control! On this image LPFP pump is not active so LP is failing while HP is rising.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule
Posted: Wed Dec 09, 2020 8:36 pm
by AndreyB
it runs!
That's rusEFI GDI PT2001 board providing high voltage peak & hold GDI control, both low and high pressure pumps are controlled by microRusEFI itself.
With this we have all the building blocks - injector control, HP valve control and fuel pressure is being accounted for in fuel calculation. Next step would be adding target high pressure table and else, sky is the limit. At this point it's just one injection per cycle.
At this point GDI priority for me is pretty low. Test mule car goes into long term storage. I will soon list this exact hardware prototype on eBay just in case if some software developer would be looking to take this further.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule #64
Posted: Fri Jan 01, 2021 3:44 pm
by Bluepower
Awesome development!!
Too bad you're putting this on hold, as I'm sure that with the newer engines becoming more-and-more GDI ones, a affordable stand-alone ECU for these applications will become more interesting!
For me personally, for now the swap to a self-tuneable GDI engine is not yet that attractive, therefor sticking to the old trusted 1.8t VAG engines..
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule #64
Posted: Thu Jan 14, 2021 6:58 pm
by 960
This is really cool stuff. great work!
There are really high demand for a affordable GDI solution, so sure this would be a big hit.
Re: 2006 Volkswagen Passat 2.0 Turbo GDI test mule #64