RS2- Just had a dyno run...power down (any thoughts?)

[newsh]

Actually RS2 can be a tooth out on the timing belt which can cause loss of boost.

[jade]

Actually RS2 can be a tooth out on the timing belt which can cause loss of boost.

Yes, there is a little confusion as how to time the RS 2 worth a check

[weta.worker]

I think the ADU engine uses the G62 (engine coolant sensor) for ECU inputs rather than the MFTS. Good shout though, could be onto something there. John, have a look at this link and scroll down. The symptoms match yours and it was a shorted wire to the G62 at the back of the engine causing the problem: http://forums.quattroworld.com/s4s6/msgs/20985.phtml

Thanks! I'll take a look at this.

[weta.worker]

Yes, there is a little confusion as how to time the RS 2 worth a check

Yeah, that was one of the first things I got the 2nd mechanic to confirm (it's now at it's 3rd)

[weta.worker]

I've just been on a boost-hunt on my RS2. Tried boost leak test, new OEM N75, new rebuilt wastegate with new spring, all new lines including to the MAP sensor. Turned out it was the hall sensor, even though the car ran fine and purred like a cat. - at 0.4bar of boost. Replaced it the other day and it's finally back til full boost...

Ahh, interesting. Does this not come up in a scan? Same with knock sensors or MFTS?

Sounds like I've got a few good leads though.

Thanks guys!

John

[weta.worker]

BTW
What do you mean you can hear the wastegate?

Sorry, I can hear the blow off \ chatter of something building boost and releasing.

[twoqu]

Going back to the ecu.
Of course it is possible that someone has just replaced the metal cover with the p/n label onto a lesser models electronic guts. Its difficult to tell just by looking at it and then there is the issue of pre-production if its that early.
As far as I know the ecu ID is written on the fuel/ign chip. So if you for example fitted a 551B chip into a 551C ecu it would identify as a 551B.
A previous member has flaggd up that the ecu appears to have a 250kpa map sensor not the 300kpa one. The additional label on it does not correspond to the Bosch one of 0273 003 211. It is possible I understand to rescale this type of map sensor by opening it up and then resealing it. Again difficult to tell whether this has been done.
The only other difference I can think of between a RS2 ecu and a normal 20V ecu is that they also changed a resistor for the maf reading. Unfortunately this is I think only visible by complete removal of the boards from the casing as its on the bottom. There is a way of measuring the value from the ecu pins but I will need to try and find that again as thats easier than dismantling the ecu further.
If someone has given the chips for the 551C version then I think that would not allow the car to start. Another potential problem would be if they were put in the wrong way round!
I have had a look at a 551C version ecu with a build date of about 6 months later. The label does not have the POR on it.
The map sensor has the part designation mentioned previously with 300kpa clearly marked on it and a red dot in two corners. The chips have the usual silver labels on them with their 1 267 XXX XXX designations on them. The ign/fuel chip also has 129 in green stamped on it!
So it might be worth investigating what effect either the incorrect map sensor and/or the resistor difference might have and whether it is consistant with your issues. It might also be useful to acquire a eprom programmer and eraser considering your remoteness. Its a lot easier to send files for you to try and conversely you can send files to be read. Its a relatively small investment considering what you must have spent already and you are then in control.

[twoqu]

I think this is the way to check the resitor mentioned previously. It should allow you to at least eliminate one of the issues mentioned previously:

http://store.034motorsport.com/blog/diy-034efi-c4-audi-urs4urs6-aan-rs2-chipset-installation-instructions/

There is an error I believe in their labelling as there are only 19 pins on the bottom row, so pin 20 should be the first pin on the right on the second row!
I have the following measurements taken between pin 7 and 25 in comparsion:

RS2 ecu 18.45K
Std ecu 19.10K

So all I can say is that there is a measurable difference between those two pin readings IF this is a valid test.

[weta.worker]

Thanks! Lots of tech data there.

Not sure if it's helpful, but here are some shots of the inside of the ECU

[twoqu]

http://www.s2forum.com/forum/showpost.php?p=828719&postcount=319

As I said previously, looking at it tells us nothing besides the resistor in question is on the underside. You will have to measure something. The resistor difference is in theory @0.6K (6.2k vs 5.6K). This is something that can be done with a multimeter.
I tried this test on another ecu which does not have a map sensor fitted and could not get a reading which suggests there is some connection with the map sensor!

[twoqu]

The only other visual difference that jumps out is that on your ecu board it has the Motronic version 2.3.2 in a black box where it says FU on the board. Neither of the ecu's I have opened have that label. That said I have not seen inside every ecu that Bosch made!

[newsh]

I don't understand why the ECU has a 250kpa map sensor.
I've just read the whole thread again..
No boost after painting could mean something has got broken, if headlights were removed maybe N75 has got disconnected.

[weta.worker]

I don't understand why the ECU has a 250kpa map sensor.
I've just read the whole thread again..
No boost after painting could mean something has got broken, if headlights were removed maybe N75 has got disconnected.

Thanks , yup, the headlights def got removed